Battle Mechanics

 Order of Attacks
 Technique Selection
 Type Vs. Type Effectiveness
 Physical Attacks vs. Special Attacks
 Pokemon Statistics
 The Big Picture
 Traded Pokemon in Battle
 Status Ailments
 Technique PP
 PP Ups
 Technique Power
 Critical Hits
 Damage Calculation Formula
 Technique Accuracy
 Attribute-Affecting Techniques
 Calculated Techniques
 Multi-Turn Techniques
 Multi-Hit Techniques
 Status-Affecting Techniques
 Switching
 Special Techniques
 Catching Pokemon
 Experience & Money Received
 Wild Pokemon & Items Attached
 Time Capsule Items
 Item Effects

Now that we have beat Stat Mechanics into the ground, let's move on to Battle Mechanics. Some of the concepts are very easy to grasp, while others will take careful study on your part.

Order of Attacks

The Order of Attacks is the Order in which an attack is processed. The game goes through this procedure every time an attack is used. Even the enemy has to go through this. Here is the Attack Order:

1. Does the attack have any effect?

The game checks to see that if your ID doesn't match the Pokemon's, do you have the right badge to control the traded Pokemon. If not, a random number is made. If the random number is greater than the Pokemon's level, he will disobey your commands. After that, if you pass this test, the game checks to see if the attack is asleep. If so, all attacks will fail, except for Snore or Sleep Talk. Also, if you Pokemon is asleep, it checks to see if it awakes. Pokemon stay asleep anywhere from 1 to 7 turns. Also, freeze healing is calculated here. You have a 10% chance of thawing each turn of battle in regular conditions (no weather).

2. Check PP

If there is no more PP for any of the attacks, the move "Struggle" is used. It has no PP. If there is PP, then the PP is subtracted 1.

3. Attack is used.

The game displays, "[Pokemon] used [Attack]!"

4. Is it a Critical Hit?

The game now checks to see if your move did a Critical Hit. Refer to the Critical Hit section to learn how this is done.

5. Damage Calculation

This is where the game does the first part of damage calculation. The rest is calculated later.

6. Damage Revision

Now the raw damage above is adjusted according to other facts, like what weather is active, which badges you have, type effectiveness, and the like.

7. Random Number

After all of that, the game picks a random number in between 217 and 255. It is multiplied by all of the above Damage Calculation, which is then divided by 255.

8. Accuracy

The following scenarios will have weird effects on the Accuracy of a move.

*Using Dream Eater on an awake opponent will fail.
*If the opponent has used Protect or Detect, the attack will fail.
*If the attacker has used Mind Reader or Lock-On, attacks will hit a flying Pokemon (except for Earthquake, Fissure, or Magnitude).
*Dream Eater of Absorb on a substitute will fail.
*By themselves, only Gust, Thunder, Twister, and Whirlwind can affect flying Pokemon.
*By themselves, only Earthquake, Fissure, and Magnitude can affect digging Pokemon.
*During Rain Dance, Thunder's Accuracy is 99.6%.
*Swift, Vital Throw, and Faint Attack are always 99.6% accurate.

Then, the accuracy ratio is determined. See Accuracy-Lowering & Evade-Boosting Techniques section for the accuracy ratio. If the opponent has Bright Powder attached, accuracy is reduced by 20/256 (7.8%). If a random number is equal to or less than the calculated Accuracy, attack will hit.

9. Additional Effects

If the attack has additional effects, their probability is calculated here.

Type Vs. Type Effectiveness

In Pokemon, plain power is not the only thing affecting damage in battles. If you type match properly, a relatively weak Pokemon can beat a relatively strong Pokemon. Also, if the attack type matches one of you Pokemon's types, the attack will cause 50% more damage. This includes Normal attacks. Here is a chart of how different attack types affect certain enemies:

RBY TypeEff

 

N

O

R

F

I

R

W

A

T

E

L

E

G

R

A

I

C

E

F

I

G

P

O

I

G

N

D

F

L

Y

P

S

Y

B

U

G

R

C

K

G

H

O

D

R

A

NOR

 

 

 

 

 

 

 

 

 

 

 

 

.5

0

 

FIR

 

.5

.5

 

2

2

 

 

 

 

 

2

.5

 

.5

WAT

 

2

.5

 

.5

 

 

 

2

 

 

 

2

 

.5

ELE

 

 

2

.5

.5

 

 

 

0

.5

 

 

 

 

.5

GRA

 

.5

2

 

.5

 

 

.5

2

.5

 

.5

2

 

.5

ICE

 

 

.5

 

2

.5

 

 

2

2

 

 

 

 

2

FIG

2

 

 

 

 

2

 

.5

 

.5

.5

.5

2

0

 

POI

 

 

 

 

2

 

 

.5

.5

 

 

2

.5

.5

 

GND

 

2

 

2

.5

 

 

2

 

0

 

.5

2

 

 

FLY

 

 

 

.5

2

 

2

 

 

 

 

2

.5

 

 

PSY

 

 

 

 

 

 

2

2

 

 

.5

 

 

 

 

BUG

 

.5

 

 

2

 

.5

2

 

.5

2

 

 

.5

 

RCK

 

2

 

 

 

 

.5

 

.5

2

 

2

 

 

 

GHO

0

 

 

 

 

 

 

 

 

 

 

 

 

2

 

DRA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

GSC TypeEff

 

N

O

R

F

I

R

W

A

T

E

L

E

G

R

A

I

C

E

F

I

G

P

O

I

G

N

D

F

L

Y

P

S

Y

B

U

G

R

C

K

G

H

O

D

R

A

D

R

K

S

T

L

NOR

 

 

 

 

 

 

 

 

 

 

 

 

.5

0

 

 

.5

FIR

 

.5

.5

 

2

2

 

 

 

 

 

2

.5

 

.5

 

2

WAT

 

2

.5

 

.5

 

 

 

2

 

 

 

2

 

.5

 

 

ELE

 

 

2

.5

.5

 

 

 

0

.5

 

 

 

 

.5

 

 

GRA

 

.5

2

 

.5

 

 

.5

2

.5

 

.5

2

 

.5

 

.5

ICE

 

.5

.5

 

2

.5

 

 

2

2

 

 

 

 

2

 

.5

FIG

2

 

 

 

 

2

 

.5

 

.5

.5

.5

2

0

 

2

2

POI

 

 

 

 

2

 

 

.5

.5

 

 

2

.5

.5

 

 

0

GND

 

2

 

2

.5

 

 

2

 

0

 

.5

2

 

 

 

2

FLY

 

 

 

.5

2

 

2

 

 

 

 

2

.5

 

 

 

.5

PSY

 

 

 

 

 

 

2

2

 

 

.5

 

 

 

 

0

.5

BUG

 

.5

 

 

2

 

.5

.5

 

.5

2

 

 

.5

 

2

.5

RCK

 

2

 

 

 

2

.5

 

.5

2

 

2

 

 

 

 

.5

GHO

0

 

 

 

 

 

 

 

 

 

2

 

 

2

 

.5

.5

DRA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

 

.5

DRK

 

 

 

 

 

 

.5

 

 

 

2

 

 

2

 

.5

.5

STL

 

.5

.5

.5

 

2

 

 

 

 

 

 

2

 

 

 

.5

Physical Attacks vs. Special Attacks

Physical attacks, as discussed before, depend on the Attack and Defense stats. Special Attacks depend of the Special stats. This info could help you better choose a Pokemon's attacks. For example, Kingler's Attack stat is much higher than its Special Attack, so it could better use a move like Body Slam instead of a move like Surf. Keep this in mind as you choose attacks. Also, not only can you use your stats to gain an advantage. For example, most Psychic type Pokemon have an extremely low Defense, so a will placed Physical blow could take one out easily. If you know your enemies weakness, you can use them to your advantage. Although, some Pokemon have enough power to not need to use their enemies' weaknesses. For example, Mewtwo can easily defeat another Pokemon that has a high Special Defense by using Special attacks. Finally, it's generally a good idea to have at least one of the opposite attack types on each Pokemon. That way, you will always be prepared for any event.

Pokemon Statistics

Also, when selecting a Pokemon's techniques, make sure to include all of its Stats into your thinking. For example, some strategies require some setup moves. If the Pokemon that will use this strategy can't last two turns in battle, the strategy will fail. Hitmonlee is a prime example. He has an excellent Attack stat, but a low Defense and HP. These facts make it plain that Hitmonlee would die quickly if any type of setup were attempted. He should mainly focus on attacking with everything he has. Some Pokemon are perfect for setup, though. Snorlax is a very good example. His high Special Defense and HP make him an excellent setup fighter. When coupled with Curse and Rest, he can very easily take damage and deal it back out easily. Attack Leftovers to him and you have a tank that can take out a lot of Pokemon once setup. So when you consider a certain strategy, make sure to pay attention to all the stats.

The Big Picture

Also, you must consider how all of your attacks affect each other. For instance, if you plan on putting the enemy to sleep, don't put Body Slam on the Pokemon as well. Body Slam has a chance to paralyze the enemy, and once paralyzed, they can't be put to sleep. Another move with no side effects would be better. Also, experiment with moves and see how different effects work together. For example, using Spikes with Toxic is a good way to hurt your opponent badly. If you opponent switches to get rid of Toxic, the Spikes will hurt it, and if he doesn't, the Toxic will finish him off. Don't forget to plan for some of your weaknesses. For example, if a Snorlax only gas Normal-type moves, he'll have no chance against Ghost-types easily. But, don't go overboard in your planning, though. Unless it's stupid in the head, a Parasect won't even think about taking on a Moltres, so don't worry on planning about this event. A smart trainer would switch to either a Water Pokemon or Ground/Rock Type Pokemon who has Rock Slide. This leads to team planning. When planning a team, don't just throw the Pokemon together. Consider all of the Pokemon's moves when you plan a team. Your team should be as flexible as possible, but don't go crazy with this.

Traded Pokemon in Battle

As discussed earlier, in order to control traded Pokemon, you must have the correct Badge. If you don't, there is a 191/256 chance (74.6%) that it will not listen to you.

Status Ailments

Sometime during one of your many battles, a Status Ailment will afflict your Pokemon. These ailments hinder Pokemon in a specific way, each changing how a Pokemon performs in battle. There are two types of Status Ailments: Fixed and Free. The difference of the two is simple. Fixed Ailments are permanent for the whole battle, and in In-Game battles, they last even after battles. Here is the list of Fixed Status Ailments and their effects:

Paralysis (Par)

This Ailment is often linked with Electric attacks. It firstly reduces the affected Pokemon's Speed by 75%, leaving it with only 25%. After that, you Pokemon won't be able to Attack or use Techniques 25% of the time. This does not apply to the other Menu's and commands, although Paralyzed Pokemon can't escape battles easily. Back to the Speed reduction, read the info about Burns and Attack modifiers, as the same rules apply to them as do Paralysis and Speed. In conjunction with Rest, in the game, it only removes the PAR status condition, not the Speed reduction. Switching after this will fix the Speed, however. This is in the RBY game, as well. Haze, when used by the enemy, clears all of the negative Paralysis effects away, while if it is used by the Paralyzed Pokemon, Haze will only get rid of the Speed reduction, and not the PAR status. If you switch after this, however, the speed penalty will reinstate itself. In Stadium 1, though, Rest removes the PAR and the Speed penalty.

Here is a list of all the moves that could cause Paralysis:

Thunder Punch
Thundershock
Thunderbolt
Tri Attack
Body Slam
Thunder
Lick
Spark
Dargonbreath
Thunder Wave
Stun Spore
Zap Cannon

Poison (Psn)

This Ailment is often linked with Poison attacks, but can't be afflicted onto Poison type Pokemon. This ailment is slow, but effective. Every time your Pokemon's turn ends, while he's Poisoned and the active Pokemon, he will lose 1/16 of his Max HP from his Current HP in RBY. In GSC, this percentage is 1/8. Outside of battle, the affected Pokemon loses 1 HP for every 5 steps taken.

Here is a list of all the moves that could Poison:

Acid
Twineedle
Poison Sting
Sludge
Sludge Bomb
Smog
Poison Powder
Poison Gas

 

Burn (Brn)

This Ailment is directly linked to Fire attacks, with the exception of Tri-Attack in GSC. To this end, only Tri-Attack can burn a fire-type Pokemon. It works almost the same as Poison in the respect that in battle, while the enemy is Burned and the active Pokemon, it loses 1/16 of its Total HP from its Current HP every time its turn ends in RBY. In GSC, that percentage is 1/8. It doesn't lose HP out of battle, though. Additionally, a burned Pokemon's Attack stat is halved, as long as there are no other Statistic modifiers in play. If there are, here are some guidelines to help you find your Attack Modifiers. First, find your modifier for Attack based solely on the Attack modifiers that have been used. Then, if the last modifier used was an increaser, use the Normal Attack stat. If you are in a link battle, and if the last modifier used was a decreaser, use the halved Attack stat. If your in a wild battle, all Attack mods apply to the Normal attack value. All of the above mentioned process can be applied to Paralysis and Speed.

Here is a list of all the moves that could Burn:

Fire Punch
Ember
Flamethrower
Fire Blast
Flame Wheel
Tri Attack
Sacred Fire

Sleep (Slp)

A great many different types of attacks use this Ailment, but the main one is the Grass type move Sleep Powder. Sleep totally immobilizes the enemy anywhere from 1 to 7 turns in the game, not including the turn needed to wake up in RBY. In Stadium 1, the duration is 1 to 4 turns. This effect will end sometime in those 7 possible turns, without the aid of an item. Any turn you don't select the Fight command is not counted as a turn asleep. The number of turns is calculated randomly, every number of turns has an equal chance of being selected. When you switch a sleeping Pokemon out then in, the counter is reset, and the duration recalculated.

Here is a list of all the moves that cause Sleep:

Hypnosis
Sing
Sleep Powder
Spore

Freeze (Frz/Ice)

This is a rare effect that is attributed to Ice techniques, although Ice types can not be frozen by moves other than Tri-Attack. It totally disables the affected Pokemon. A frozen Pokemon can be thawed out by either using an item or held item, to be hit with a Fire technique after being frozen, or to know the move Flame Wheel or Sacred Fire in GSC. Also in GSC, a Pokemon has a 10% chance of thawing out every turn frozen, unless Rain Dance is in effect. Then, you can't unfreeze until the effect of Rain Dance ends.

Here is a list of all the moves that could Freeze:

Ice Punch
Ice Beam
Blizzard
Powder Snow
Tri Attack

Unconsciousness (Fnt)

Whenever a Pokemon's HP hits 0, it Faints and is unable to battle any further until it is rejuvenated either at a Pokemon center or by a Revive, Max Revive, Revival Herb, or Sacred Ash. This Ailment overwrites all other Ailments, Fixed or Free.

As mentioned before, Fixed Stats Ailments last even after battle. The PokeCenter should be able to cure them, though. Also, as discussed before, items can be used to heal the Pokemon. One Status Ailment can only affect a Pokemon at a time, and once infected with one Ailment, any other, besides Faint, can't overwrite it.

Free Status Ailments differ from Fixed Ailments in that they wear off after battle. They also can be removed by switching to another Pokemon. Fainting cancels all Free ailments. Here is a list of the Free Status Ailments and their effects:

Leech Seed

Whenever a Pokemon is hit by Leech Seed, it is seeded. Every time that Pokemon's turn ends, the Pokemon loses 6.25% of its Max HP from its Current HP. These lost HP are actually given to the opponent Pokemon. Pokemon of the Grass Type can't be affected by this technique.

Bad Poison (Psn)

Whenever a Pokemon is hit by Toxic, it is Badly Poisoned. It stats the same as normal Poison by taking 1/16 of the Pokemon's Max HP from its Current HP. After that, the percentage doubles the 2nd turn, triples the 3rd turn, and so on until it does 100% damage on the 16th turn. This Status Ailment can't be overwritten. When this Bad Poison wear's off, it changes to Normal Poison. Again, Poison Pokemon can't be poisoned in any way, Badly or Normal.

Hold

In RBY, moves like Wrap and Bind held a Pokemon. While held, Pokemon cannot attack or use any techniques. These effects usually last any where from 2 to 5 turns. In GSC, they don't lock out techniques or attacks. They just prevent the Pokemon from running or switching. In both cases they cause damage to the enemy every turn.

Flinching

Some attacks cause the enemy Pokemon to Flinch. When the Pokemon flinches, its technique selection for that turn is negated. This affect only affects one turn. Also, the King's Rock item can cause certain attacks to cause the enemy to Flinch. A note on flinching: your attack must hit first for it to have a chance of flinching. If you are slower than the enemy, it won't work.

Here is a list of the attacks that cause Flinches:

Bite
Bone Club
Headbutt
Hyper Fang
Low Kick
Rock Slide
Stomp
Twister

Confusion

This ailment causes the enemy to become confused for 1 to 4 turns, determined randomly. While confused, the Pokemon has a 50% chance of hitting itself. The damage done to yourself has a 40 power, Physical, not effected by Reflect in RBY, considered Typeless, doesn't Critical Hit, and damage isn't random.

Here is a list of the attacks that cause Confusion:

Confuse Ray
Confusion
Dizzy Punch
Dynamicpunch
Psybeam
Supersonic
Sweet Kiss

Curse

This ailment causes the enemy to become cursed. Curse will only curse Pokemon if a ghost-type is using the move. While Cursed, you will lose 1/4 of your HP every turn. The Ghost who uses Curse, however, loses 1/2 of its HP to curse you.

Nightmare

This ailment, caused by the move Nightmare, has the same effect as a Ghost-type Pokemon using curse, just with a few exceptions. The user doesn't lose half its HP, but the enemy must be asleep for the effect to affect the enemy. If he wakes up, Nightmare is disrupted.

Attract

This ailment, caused by the move Attract, will only affect a Pokemon who is the opposite gender of the attacker (i.e. no legendaries will be affected by this move, as well as genderless Pokemon). Once attracted, the enemy has a 50% chance each turn of not attacking because of its attraction to the opponent.

Remember, only one Fixed Status Ailment may affect a Pokemon, but any number of Free Status Ailments can affect that same Pokemon. Mix and match them to find combinations that work.

Technique PP

Even if a Pokemon has full HP, it still may not be able to attack. Each technique has a rating called PP, or Power Points. This is the number of times the attack can be used before it tires out. If all techniques run out of PP, a move called Struggle is used. It does minimal damage, is Typeless, and has a recoil effect. Base PP can range from 1 to 40.

PP Ups

There are rare items that are found in the Pokemon world. These are known as PP Ups. They affect only one Particular technique. It increases its Max PP by 20% with each use, but a technique can only be increased 3 times, giving a technique 60% more PP. These items are rare, and any new moves that replace PP upped moves will not gain the boost. Choose whom you give it to, and which move you give it to, carefully.

Technique Power

Most techniques that you will use the most have an attribute called Power. This attribute helps control how strong an attack is. Some attack power, like Scratch and Pound, aren't that strong. Others, like Explosion and Self Destruct, are very powerful. Here is a list of all the attacks attributes, including a description of the moves effects:

RBY Attack Attribute Chart

GSC Attack Attribute Chart

Also, some moves and items can increase the power of moves, while other moves can reduce a technique's power. Here are the items that affect the power of certain moves of certain types:

Type

Item

Normal

Pink Bow

Normal

Polkadot Bow

Fighting

Blackbelt

Flying

Sharp Beak

Poison

Poison Barb

Ground

Soft Sand

Rock

Hard Stone

Bug

Silver Powder

Ghost

Spell Tag

Steel

Metal Coat

Fire

Charcoal

Water

Mystic Water

Grass

Miracle Seed

Electric

Magnet

Psychic

Twisted Spoon

Ice

Nevermeltice

Dragon

Dragon Fang

Dark

Dark Glasses

There are no moves that modify a moves power directly. Rain Dance and Sunny Day modify part of the damage, but not the power directly.

Other moves' power change based off of other variables. For example, Reversal's and Flail's power both increase as its HP decreases. Also, Fury Cutter and Rollout have a power that increases with repeated uses, but resets if the move misses. Triple Kick starts with a Base Power of 10, then the next hit doubles to 20, and on the third hit has a Base Power of 40. Counter and Mirror Coat go last, and deal back the damage double to what they have received. There may be others, but they will be covered under the Special Techniques section.

Critical Hits

Every once in awhile, your attack will Critical Hit. When it does, your damage is nearly doubled. Critical Hits multiply the raw damage by 2 somewhere in the Damage Calculation Formula. In RBY, stat modifiers are ignored. Also, critical hits are based on a Pokemon's Base Speed and other modifiers. Here is the RBY Critical Hit formula:

N = int(( int( int( S / 2 ) * M ) / 256 ) * 100 )

where N is the Critical Hit percentage, S is the Pokemon's Base Speed, and M is the Critical Hit Modifier. M is calculated by starting at 1. In RBY, if Focus Energy has been used, divide M by 4. This is a bug. In Stadium 1, if Focus Energy has been used, multiply M by 4. If the attack being used is either Karate Chop, Slash, Razor Leaf, or Crabhammer, multiply M by 4.

A random number, from 0 to 255, is made. If the number is less than S after is has been multiplied by M, the attack is a Critical Hit.

In GSC, critical hits are in no way connected to speed. Critical Hits in GSC don't totally ignore modifiers. What happens is it calculates both with and without the Stat modifiers. Which ever is greater, it uses.

Critical Hits are determined based on a variable N and a random number, which can only be 0 to 255. If a Critical Hit Number is greater than the random number, the attack Critical Hits.

N is calculated as follows:

N starts at 0.

If Focus Energy has been used, add 1 to N.

If the Attack is either Karate Chop, Razor Leaf, Crabhammer, Slash, Aeroblast, or Cross Chop, add 2 to N.

If Scope Lens in equipped, add 1 to N.

Finally, if Chansey has Lucky Punch or Farfetch'd has Stick, set N to equal 2.

After determining N, use it to find the Critical Hit Number:

N

Crit Hit Number

0

17

1

32

2

64

3

85

4

128

Damage Calculation Formula

My favorite formula in Pokemon, the Damage Calculation Formula is also probably the most complex in the game. Even now, new research is still being conducted. All I can give you is what I know and have seen.

According to Meowth346, the first thing to check in the game is whether the attack is Physical or Special. This is based on the Attack's Type. If the Attack Type is Normal, Fighting, Flying, Poison, Ground, Rock, Bug, Ghost, or Steel, then the attack is Physical. If the Attack Type is Fire, Water, Grass, Electric, Psychic, Ice, Dragon, or Dark, then the attack is Special.

Next, the game checks for Pokemon obedience.

Then, the game displays the attack used on the screen.

Fourth, the game checks the amount of PP the move has. If all skills have 0 PP, then Struggle is used. Otherwise, 1 is taken from the Attacks PP rating. When one skill has 0 PP, you get the message, "There's no PP left for this move!"

Fifth, the game checks for Critical Hits.

Sixth, the game calculates something called raw damage using this formula:

(int(int(int(Level * 2 / 5 + 2) * AttackStat * SkillPower / DefenseStat) / 50) + 2)

The variables should be self explanatory. For critical hits, add a * 2 to the end of the formula. If the attacking Pokemon uses either Explosion or Self Destruct, then the opponent's Defense is divided by 2. If Pikachu has the Light Ball, then its Special Attack is doubled. If Cubone or Marowak has the Thick Club, then its Attack is doubled. If Ditto has the Metal Powder, then its Defense and Special Defense both are multiplied by 1.5. If the Defending Pokemon has used Reflect, then the DefenseStat is multiplied by 2 (still being affected by the Stat Cap). If the Defending Pokemon has used Light Screen, then its Special Defense is multiplied by 2. All of this is checked before the formula is used. Also, if either the Attack or Defense stat is equal to or over 256, both are divided by 4. If you don't know, AttackStat means the attacking Pokemon's Attack stat, whether it is Attack or Special Attack. Also, DefenseStat means the defending Pokemon's Defense stat, whether it is Defense or Special Defense. After being divided by 4, if the stats are still equal to or above 256, keep subtracting 256 from the above stat until it is less than 256. Also, if either stat is 0, sit that stat to 1 to prevent division problems. Now, if the power up item's type matches the Attack's Type, then multiply the damage so far by 1.1. Finally, if the raw damage is over 997, set it to 997. This applies before the + 2 in the Raw Damage Formula, so it will become 999.

 

After all of that, now the damage is revised again. The game now performs a weather modifier operation on the raw damage. If Rain Dance has been used, all Water-Type Attacks that deal damage here get multiplied by 1.5, while all Fire-Type Attacks that deal damage here get multiplied by .5. The opposite is true while Sunny Day is in effect, where Fire-Type Attacks are multiplied by 1.5 and Water-Type Attacks are multiplied by .5. With the correct badge and Skill Type in the Game, an attack gets multiplied by 9/8. Here is a list of the Badges and the types they affect:

Badge

Type to Receive Bonus

Zephyr Badge

Flying Type Skills

Hive Badge

Bug Type Skills

Plain Badge

Normal Type Skills

Fog Badge

Ghost Type Skills

Mineral Badge

Steel Type Skills

Storm Badge

Fighting Type Skills

Glacier Badge

Ice Type Skills

Rising Badge

Dragon Type Skills

Boulder Badge

Rock Type Skills

Cascade Badge

Water Type Skills

Thunder Badge

Electric Type Skills

Rainbow Badge

Grass Type Skills

Soul Badge

Poison Type Skills

Marsh Badge

Psychic Type Skills

Volcano Badge

Fire Type Skills

Earth Badge

Ground Type Skills

Then, if the Attack Type matches one of the Attacking Pokemon's types, multiply the damage by 1.5. This is called Same Type Attack Bonus, or STAB for short.

Next, the game uses those type effectiveness charts found earlier. The effect will either be these numbers: 4, 2, 1, .5, .25, 0. One of those will multiply times the damage so far. Refer to the charts found earlier for an explanation on how to find this number. Also note that Foresight allows Normal and Fighting-Type attacks to hit Ghost-Type Pokemon.

Then, and this only applies in GSC, the game does a Rage check. In RBY, whenever Rage built, all it would do is raise the Attack Stat modifier. In GSC, however, every Rage build adds one to a special variable. Then, to keep from having multiplication problems, the game adds one more to the variable. It is then multiplied into the damage.

Finally, the damage may lose a few damage points. The game creates a random number that is from 217 to 255. It multiplies this number times the damage, and then divides it by 255.

After that, the game performs a Hit Check, or checks for accuracy.

Finally, after the damage is applied and the attack actually hit, any additional effects are applied if the work.

Technique Accuracy

As well as Base Power, all techniques have a Base Accuracy that helps determine the accuracy of a move. Some moves, like Scratch and Pound, have an almost perfect accuracy, while others, like Blizzard and Thunder, have a lowered accuracy. Some moves are not affected by moves like Double Team or Sand Attack, like Swift or Faint Attack. Here is a chart explaining how moves like Double Team and Sand Attack affect accuracy:

Stage

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

Accuracy Change

3/9

3/8

3/7

3/6

3/5

3/4

3/3

4/3

5/3

6/3

7/3

8/3

9/3

Evasion Change

9/3

8/3

7/3

6/3

5/3

4/3

3/3

3/4

3/5

3/6

3/7

3/8

3/9

You start at Stage 0, with the Accuracy Change half of the chart. You find your Accuracy number by looking up your stage and going down to the Accuracy Change chart. Then, start back at Stage 0, this time with the Evasion Change half of the chart. Look up your Evasion number. Then, to calculate the real accuracy of a technique use this Formula:

RealAccuracy = BaseAcc * Acc# * Ev#

Go back to Technique Power to find a technique's BaseAcc in the chart. If a random number, from 1 to 256, is less than or equal to the RealAccuracy number, then the attack hits. If the random number is greater than the RealAccuracy number, then the attack misses.

To find an accuracy percentage, divide the RealAccuracy number by 256, and then multiply by 100 to change the decimal to a percentage.

Note: Moves like Swift and Faint Attack are ignored in the Accuracy and Evasion calculation, but they can miss. Their Base Accuracy is 255, the max a move's accuracy can be. But, the random number can be a max of 256, meaning that if you get 256 with Swift, you will miss. Your chances of missing are 1 in 256. It is extremely hard to get that, but it is possible.

1-Hit K.O. Techniques

1-Hit K.O. techniques are special attacks that, if they hit, instantly reduce the opponent's HP to zero, no matter how high it started off at. The problem with these moves is all of their accuracies are 29.6%, making them all most impractical to use. In RBY, accuracy of these moves was affected by the Pokemon's actual speed. If the attacking Pokemon's speed is greater than or equal to the defending Pokemon's speed, then the 1-Hit K.O. technique's accuracy it 29.6%. Otherwise, the attack has no chance of hitting. Also, moves affecting the Speed of a Pokemon could give a Pokemon that had no chance some chance of hitting with the 1-Hit K.O. Also note that the highest their accuracy can get is 29.6%. It cannot be raised past this or lower from this, except to 0 if the attacker's speed is less than the defender's. In GSC, however, these moves accuracy are determined based on the attacker's level. The accuracy of these moves is 76/256 when the levels equal each other. If the Defender's level is higher than the Attacker's level, then the accuracy is 0. When the attacker's level is higher than the defender's, the following formula is used:

Accuracy = (76 + (Attacker'sLevel - Defender'sLevel)) / 256

Attribute-Affecting Techniques

Here is a list of the techniques that can alter the attributes of the attacking or defending Pokemon, what attribute they affect, how they affect it, and how much of a chance they have of affecting it:

Attribute-Affecting Chart

To explain how this works, each Attribute (Attack, Defense, Speed, Special [RBY] or Special Attack [GSC], Special Defense [GSC], Evasion, and Accuracy) can be altered in battle by the afore mentioned techniques. The effect is counted in Stages:

Stage

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

Effect

2/8

2/7

2/6

2/5

2/4

2/3

2/2

3/2

4/2

5/2

6/2

7/2

8/2

Percent

25%

28%

33%

40%

50%

66%

100%

150%

200%

250%

300%

350%

400%

To see how your stat is effected by this, take the Actual Stat your Pokemon has, then multiply it by the Effect value. You can only raise to 6 or lower to -6 in Stages, no higher or lower.

Calculated Techniques

Most attacks are affected by stats and level, but a few deal fixed, or calculated, damage. These moves do a set amount of damage every time they are used. Nothing can affect them, not even type changes. Here is a list of the Moves and how they figure damage:

Technique

Method for Damage Calculation

Super Fang

Enemy HP = int(EnemyCurrentHP / 2)

Seismic Toss

Damage = User's Level

Nightshade

Damage = User's Level

Sonicboom

Damage = 20

Dragon Rage

Damage = 40

Multi-Turn Techniques

Some moves can attack you multiple times on different turns for each attack. These techniques are called Multi-Turn Techniques. These include moves like Fire Spin and Wrap. These attacks last for 2 to 5 turns. In RBY, the opponent could do nothing while "trapped", while in GSC, the enemy can do everything besides switching. When these attacks affect the enemy, he loses 1/16 of his Max HP from his Current HP. Here is a list of the moves that have this effect:

Bind
Wrap
Fire Spin
Clamp
Whirlpool

Multi-Hit Techniques

These, like the above techniques, attack the enemy multiple times. These, however, effect the enemy in one turn. The damage caused is calculated every time it hits. It has a chance of hitting 2 or 3 times 37.5% of the time, and 4 or 5 times has a 12.5% chance. It will always hit at least 2 times, but not more than 5. Here is a list of techniques that have this effect:

Doubleslap
Comet Punch
Fury Attack
Pin Missile
Spike Cannon
Barrage
Fury Swipes
Bone Rush

Status-Affecting Techniques

This is a list of all techniques that can cause status changes. This is to help you figure how to best use each skill together. It will list the name, effect, & chance of effect for each of these skills. An X beside a name means this applies only to the move in GSC. Here is the list:

Status Affecting Chart

Note: The chance of effect only applies if the move hits, which may reduce a moves chances of effecting the enemy.

Switching

Some people refuse to do this in battles, but to be a good trainer, you must be able to switch your Pokemon effectively. A good time to switch is when your enemy has a type advantage against your current Pokemon. You may wish to switch to a Pokemon that is super effective against your Pokemon, but they may either switch their Pokemon or have a move on their current Pokemon that is super effective against your new Pokemon, like Raichu having Surf. Which switching method you use is up to you. What happens when you switch is Attribite-modifications, Person Evasion/Accuracy modifications, and Free Status ailments are removed (except for Toxic, which just converts back to normal poison). All other information about your Pokemon is stored and kept, including remaining HP and any Fixed Status Ailments. Also, if the incoming Pokemon has already been hurt by a Fixed Status Ailment, it is brought in with the Pokemon. Another note about switching, if your Pokemon is super effective against the Enemy, but only has about 15% of its HP left while the enemy is at full health, it may be wise to switch to a normally effective Pokemon with good attacks, as to save your weakened Pokemon But, if you want to suicide to kill you enemy, I say go for it and have fun. Pick the method that works best for you and use it.

Special Techniques

Some attacks are so different, so special, and so weird that they disserve their own separate section, which is here. Basically, these techniques didn't fit in anywhere else, so the all come here.

Hidden Power

Both the power and type of Hidden Power are determined by a Pokemon's DVs.

First, take the 4 main DV's and change them into a 1 or 0. How you do this is you take the DV, and if it is 0~7, the new number is 0, but if the DV is 8~F(15), the number is 1.

Put these 4 new numbers side by side, in Attack-Defense-Speed-Special order, and they'll be in Binary form. Convert to hex using the following chart:

Binary

Hex

0000

0

0001

1

0010

2

0011

3

0100

4

0101

5

0110

6

0111

7

1000

8

1001

9

1010

A (10)

1011

B (11)

1100

C (12)

1101

D (13)

1110

E (14)

1111

F (15)

This number is X.

Now, take you Special DV, and covert it to binary. Take the 3rd and 4th numbers here (ex. If it is 0110, take 10). Put a 00 on the left side of these two (0010), and convert back to hex (2). This number is Y.

Now just use the following formula:

int(( X * 5 + Y ) / 2) + 31

Your result is Hidden Power's base power. For the type, take the Attack and Defense DV's and convert to binary. Take the last 2 numbers of each binary DV and put them side by side, Attack on left, Defense on right. Convert back to Hex and use this chart to find the type:

F

Dark

E

Dragon

D

Ice

C

Psychic

B

Electric

A

Grass

9

Water

8

Fire

7

Steel

6

Ghost

5

Bug

4

Rock

3

Ground

2

Poison

1

Flying

0

Fighting

Reversal/Flail

These attacks do not Critical Hit. To find the base power of these moves, use the following chart:

Current HP Amount

Base Power

33/48 or More

20

17/48 - 33/48

40

10/48 - 17/48

80

5/48 - 10/48

100

2/48 - 5/48

150

Less than 2/48

200

What you do is you find your HP percent by taking the Current HP and dividing it by the Max HP. Then using the chart (changing the fractions above to decimals for simplicity sake) find your category and beside it is your Base Power, which should plug into the Damage Formula quite nicely.

Endure/Protect/Detect

These attacks have a decreasing accuracy with consecutive uses. If follows this pattern:

99.6 % > 49.6 % > 24.6 % > 12.1 % > 5.9 % > 2.7 % > 1.2 % > 0.4 %

These techniques also strike before Quick Attack, Mach Punch, and Extremespeed. You cannot use them together (i.e. Protect, Enure, Protect, Endure). I suppose you must use an actual attacking move in between uses to reset the counter back to no uses.

 

Magnitude

Based on the strength, of magnitude, use the following chart to find the Base Power:

Magnitude

Power

Probability

4

10

5.5%

5

30

9.8%

6

50

19.9%

7

70

30.1%

8

90

19.9%

9

110

9.8%

10

150

5.0%

Note: The magnitude numbers are correct, they only go 4 to 10.

Present

This technique replaces a few variables in the damage formula, which are listed out in the following chart:

Old Variable

Replaced With

Attacker's Attack

10

Defender's Defense

Attacker's Attribute # of Second Type

Attacker's Level

Defender's Attribute # of Second Type

If you have a 0 anywhere in the formula, replace it with 1.

Use the next chart to find an attribute number:

Physical Type

Special Type

Normal - 0

Fire - 20

Fighting - 1

Water - 21

Flying - 2

Grass - 22

Poison - 3

Electric - 23

Ground - 4

Psychic - 24

Rock - 5

Ice - 25

Bug - 7

Dragon - 26

Ghost - 8

Dark - 27

Steel - 9

Note: The use of the second type only applies to Pokemon with two different types and in Gold and Silver. This is a bug and was supposed to have been fixed in Crystal and is definitely fixed in Stadium 2.

Haze

This removes all status changes, confusion, stat modifications, and other effects from both Pokemon.

Baton Pass

This move switches the active Pokemon with a Pokemon on your belt, but it has certain advantages over regular switching:

 *Transfers all stat mods, besides those given by burns and paralysis.
 *Transfers the secondary effect of Defense Curl, which affects Rollout.
 *Transfers the secondary effect of Minimize.
 *For multi-turn attacks, the new Pokemon stays trapped. If the attacker switches in any way (including Baton Pass), the move ends.
 *The new Pokemon inherits any confusion caused by any means.
 *Transfers the effects of Foresight and Focus Energy.
 *Transfers the Nightmare effect as long as the old and new Pokemon are asleep.
 *Attract is not transferred.

Strike First Techniques

All techniques are categorized into four priority levels. The technique in the higher priority level strikes first. When the techniques are in the same level, the Pokemon with the higher speed goes first. If the speeds match and your in the same priority level, the initiative is given randomly. Here are the four priority levels:

1st

Endure, Protect, Detect

2nd

Quick Attack, Mach Punch, Extremespeed

3rd

All other attacks

4th

Counter, Mirror Coat, Whirlwind, Roar, Vital Throw

Heal Bell

This move can heal the rest of your party of any and all status conditions, except for a Ghost's Curse. Not even switching can fix that. It can not heal the using Pokemon of Sleep or Freeze, unless randomly selected by Sleep Talk.

Rain Dance

This move is a weather modifier. While in effect, which lasts for 5 turns including the turn it was used, water-attacks receive a 50% boost in damage, while attacks receive a 50% reduction in damage. Also, in "in-game" battles, it halves the effectiveness of Morning Sun, Moonlight, and Synthesis. Solar Beam's power is reduced by 50%. It also keeps a Pokemon from thawing out while in effect. Finally, as is commonly known, Rain Dance increases the Accuracy of Thunder to 99.6%, while Sunny Day decreases the Accuracy of Thunder to 49.6%. Neither of these affect power, or any other electric Techniques in any way.

Sunny Day

This move also is a weather modifier. While in effect, which lasts 5 turns including the turn it was used, Fire-Type attacks receive a 50% increase in damage, while Water-Type attacks receive a 50% decrease in damage. Also, in "in-game" battles, it makes Morning Sun, Moonlight, and Synthesis restore all HP to the user. It also prevents freezes in battles while effective. Finally, as is also commonly known, Sunny Day helps Solar Beam by making it a one-turn technique.

Softboiled & Mild Drink

In battle, these moves restore 1/2 of the user's Max HP. Outside of battle, though, it transfers 1/5 of the Max HP from the Current HP of the user to another Pokemon.

Morning Sun, Synthesis, & Moonlight

These moves heal HP, but each heals a different amount at different times of day in the game. Morning Sun heals 1/2 HP during the morning time & 1/4 HP every other time. Synthesis heals 1/2 HP during the afternoon & 1/4 HP every other time. Moonlight heals 1/2 HP during the night time & 1/4 HP every other time. They all heal 1/2 HP in link or Stadium battles, though.

RBY Recover, Rest, & Softboiled

Recover and Softboiled heal 1/2 HP, while Rest heals all HP. This is true, except when the difference between Max HP and Current HP is 511, 255, or 0 (which is fully healed). This is due to how the game checks you HP to use these moves. In Hex, 511 and 255 both end in FF, which causes the game to think that your HP is full.

Furry Cutter, Rollout, and Rollout & Defense Curl

These moves start with a low Base Power, and with each successive use, the Power doubles. Here is a chart showing these successive successful uses:

# of Uses

Fury Cutter Base Power

Rollout Base Power

Rollout + Defense Curl

1

10

30

60

2

20

60

120

3

40

120

240

4

80

240

480

5

160

480

960

Substitute

Substitute creates a small copy of your Pokemon, and gives it 25% of your Current HP. The Sub can take that much damage before finally breaking. Any extra damage done to it is just lost. Any stat mods used before the Sub is put up are given to the Sub, while the enemy's stat mods will fail after the Sub is up. Subs can not be affected by Status ailments, but the Pokemon behind the Sub can be, if it was affected before the Sub went up. Successful One-Hit KO attacks, Selfdestructs and Explosions on a Sub will only break the Sub, and the Pokemon behind it receives no damage. Substitutes do not block Haze, Whirlwind, Roar, Psyche Up, or Perish Song. It can't also be used together with Counter. Subs block all Status changes, Statistic modifiers, and secondary move ailments from the Pokemon behind the Sub. It also doesn't block the benifits of moves like Ancient Power, Steel Wing, or Metal Claw. Subs do not protect the Pokemon from a Sandstorm. Subs prevent damage from Pain Split, Mega Drain, Giga Drain, etc... Subs do receive recoil damage, but only 1 HP of it.

Beat Up

Beat Up is one of the more tweaked out Attacks in Pokemon. With Beat Up, not just the Pokemon that knows it attacks, but all the Pokemon on your belt that are not Fainted, Burned, Poisoned, Paralyzed, etc. join in as well. For this feature, however, the Damage Formula had to be tweaked just a bit. Here is the formula as it applies to Beat Up:

(((( Level * 2 / 5 + 2) * Base Attack * 30 / Base Defense) / 50) + 2)) * (217/255 ~ 255/255)

Now, for each Pokemon that is attacking, the Critical Hit check is performed, Attack and Defense Mods are ignored, Dark Glasses are ignored, Dark Pokemon receive no STAB, and opponent's Types do not affect damage. Base Attack is the Base Attack of which ever Pokemon on your Belt just happens to be attacking, and Base Defense is the Enemy's Base Defense. Level is your opponents Level.

Catching Pokemon

Sure, fainting enemy Pokemon is fun, but the true challenge is trying to catch the enemy Pokemon. There is a formula to this, but in the end, catching is determined by a random number.

The formula is as follows:

E = int((1 - A / B / 2 ) * C + D + 1)

Now, for the variables:

A is the Current HP. If A > 255, A = int(int(A / 2) / 2)
B is the Max HP. If B > 255, B = int(int(B / 2) / 2)
C is the Catch Rate, which will be explained later.
D is the Status Modifier: If Opponent is

Asleep

D = 10

Frozen

D = 10

Paralyze

D = 5

Poison

D = 5

Burn

D = 5

Else

D = 0

If a random number, from 0 to 255, is less that or equal to E, then the Pokemon is caught.
If a random number is greater than E, then the Pokemon breaks free.

So, now for the Catch Rate. If the Catch Rate calculated is greater than 255, then set the Catch Rate to 255.

First, find your Pokemon's Catch Rate in the chart below, then use the second chart to find how the PokeBall affects this number:

Catch Rate Chart

PokeBall

Modifiers

Poke Ball

C = Catch Rate

Great Ball

C = Catch Rate * 1.5

Ultra Ball

C = Catch Rate * 2

Master Ball

Wild Pokemon are instantly Caught

Heavy Ball

C = Catch Rate + Weight Bonus

Weight Bonus

-20 Any Pokemon not listed below goes here

 0 Arcanine, Machamp, Graveler, Dewgong, Cloyster, Exeggutor, Rhyhorn, Rhydon, Mewtwo, Forretress, Scizor, Ursaring, Kingdra, Donphan, Raikou, Entei, Suicune, Pupitar, Tyranitar, Ho-oh

+20 Golem, Onix, Gyarados, Lapras, Dragonite, Mantine, Lugia

+30 Snorlax, Steelix

Level Ball

If your Level > Enemy's Level, C = Catch Rate * 2

 

If your Level / 2 > Enemy's Level, C = Catch Rate * 4

 

If your Level / 4 > Enemy's Level, C = Catch Rate * 8

Love Ball

If Pokemon are Same Species, Opposite Genders, C = Catch Rate * 8

Moon Ball

If the Wild Pokemon evolves with the Moon Stone, C = Catch Rate * 4

Lure Ball

C = Catch Rate * 3 if Pokemon is fished up

Friend Ball

C = Catch Rate (Happiness is 200 for a start instead of 70)

Fast Ball

C = Catch Rate * 4 if Pokemon is Magnemite, Grimer, Tangela, Mr. Mime, Eevee, Porygon, Dratini, Dragonair, Togetic, Umbreon, Unown, Snubbull, or Heracross

Park Ball

C = Catch Rate * 1.5

Safari Ball

C = Catch Rate * 1.5

Note: The special balls that cannot be commercially bought are made by Kurt in Azalea Town with the appricorns listed in the next chart:

BLK Appricorn

Heavy Ball

RED Appricorn

Level Ball

PNK Appricorn

Love Ball

YLW Appricorn

Moon Ball

BLU Appricorn

Lure Ball

GRN Appricorn

Friend Ball

WHT Appricorn

Fast Ball

Experience & Money Received

When you defeat a wild or trained Pokemon, the game gives your Pokemon experience after the battle (this is not related to Stat Exp. gains). Use the following formula to determine experience gained:

Experience = int(((E * L) * B * T) / 7)

where E is the Base Experience for a Pokemon, L is the Level of the enemy, B is the Battle Modifier ( 1 for wild battles, 1.5 for trainer battles), and T is the ID Modifier ( 1 if your's matches your Pokemon's, 1.5 if their different). Here is a chart of all the Base Experience for all Pokemon:

Base Exp Chart

Now for the money. Use the following formula to find how much money you receive:

Money = Base Money * Level of last Pokemon on Enemy Belt

For Base Money, use the following chart:

Trainer Type

Base Money

Poke Trainer

100

Champion

100

Elite Four

100

Gym Leader

100

Rival (Johto)

60

Rival (Kanto)

100

Of course, the Amulet Coin attached to any Pokemon that battles will double the amount of money received.

Wild Pokemon & Items Attached

In the wild, some Pokemon may be holding items. You can obtain this item y either catching the Pokemon or using the technique Thief. (Note: Your Pokemon must not be holding an item in order to steal you enemies' using Thief. Items acquired in Link or Stadium battles must be returned at the end of the match.)

The items you can receive e are listed below:

Note: Pokemon with a * beside their name can't be found in the wild naturally.

Item Attached to Pokemon in Wild Chart

 

Time Capsule Items

When ever you trade a Pokemon from the past (i.e. from RBY) to the future (i.e. from GSC), they may come with an item attached. Thanks again to Meowth346, for he has discovered the secret to the list. It turns out that the Item traded over is related to the Pokemon Catch Rate in RBY. For simplicity sake, I will just give the chart that shows all of the Pokemon and what items they will have when traded over. Note: this only applies to a Pokemon from the form it was caught. Say, if you caught an Abra, and traded it to the future from the past, it would give you TM09. If this same Abra was evolved, then traded over, it would still only send TM09. If it were to be evolved into Alakazam, then tried to trade to the future, it would still hold TM09. A wild Kadabra caught in Yellow and traded, however, would give a TwistedSpoon, as it would if it were evolved before the trade to the future.

Time Capsule Items Chart

Item Effects

In GSC, items can be attached to Pokemon for battles. These items either effect the Pokemon it is attacked to, or the enemy Pokemon. Here is a list of all the attachable items and how they effect Pokemon:

Items that add 10% to attacks of their corresponding type:

Pink Bow

Normal

Route 29 / Goldenrod City

Polkadot Bow

Normal

Trade

Blackbelt

Fighting

Lake of Rage

Sharp Beak

Flying

Route 40 / Trade / Wild

Poison Barb

Poison

Route 32 / Wild

Soft Sand

Ground

Route 34

Hard Stone

Rock

Route 36

Silver Powder

Bug

Wild

Spell Tag

Ghost

Blackthorn City / Trade / Wild

Metal Coat

Steel

S.S. Aqua / Wild

Charcoal

Fire

Azalea Town

Mystic Water

Water

Cherrygrove City

Miracle Seed

Grass

Route 32

Magnet

Electric

Route 37

Twisted Spoon

Psychic

Trade / Wild

Nevermeltice

Ice

Ice Path

Dragon Fang

Dragon

Dragon's Den

Dark Glasses

Dark

Dark Cave

Berserk Gene - If this item is attached to a Pokemon, when the Pokemon is sent out the item is automatically activated without any conditions. It ups it's attached Pokemon's Attack 2 Stages, and confuses the Pokemon as well. This item can be found in Celadon City.

Berry/Berry Juice/Gold Berry - If the Pokemon holding it has a Max HP of 256 or less, when the HP gets to 1/2 or less it will start working. If you have a Pokemon who's Max HP is higher than 256, then the berries will kick in only when 128 HP has been lost. Berries heal 10 HP, Berry Juice heals 20, and Gold Berry heals a total of 30 HP. Berries can be found in the National Park, Routes 29, 30, 38, 46, 11, Mystery Gifts, and Trading.

PSNCureBerry - Removes 'Poison' status instantly after being affected. Can be found on Routes 2, 30, 33 and with Mystery Gifts.

Mint Berry - Removes 'Sleep' status instantly after being affected. Can be obtained on Route 39, Pewter City, and through Mystery Gifts.

Burnt Berry - Removes 'Frozen' status instantly after being affected. Can be found on Route 44, Fuchsia City, Pewter City, through Mystery Gifts, and Trades.

Ice Berry - Removes 'Burnt' status instantly after being affected. Can be obtained in Pewter City, Routes 36, 26, through Mystery Gifts, and Trades.

PRZCureBerry - Removes 'Paralyze' status instantly after being affected. Can be found in Violet City, Routes 46, 8, and through Mystery Gifts.

Bitter Berry - Removes 'Confusion' status instantly after being affected. Can be obtained in Blackthorn City, Routes 31, 43, 1, and through Mystery Gifts.

MiracleBerry - Removes 'Poison', 'Sleep', 'Frozen', Burnt', 'Paralyze', and 'Confusion' statuses instantly after being affected. Can only be received through Mystery Gifts.

MysteryBerry - When an attack's PP hits 0, this item will restore 5 PP to that attack. The exception is Sketch, since it only has 1 PP, only 1 PP can be restored. If more than one move run out of PP at the same time (only possible with Spite used on you), the PP of the attack higher up on the list will be restored. Can be found on Routes 35, 45, and through Trades.

Quick Claw - This gives the attached Pokemon 23.4% of a chance of attacking first. If both sides have the Claw attached, and both activate at the same time, when in "In-Game" battles, you will go first. If linked, whoever selects his/her attack first gets the 23.4% chance of going first. Can be found in the National Park and in the Wild.

King's Rock - Once attached, it gives certain attacks a 11.7% chance of causing the opponent to flinch. Attacks with extra effects will have their effects happen first. Look back at the GSC Attack Attribute list to see which attacks are affected by it. Can be found in Slowpoke Well, through Trades, and on Wild Pokemon.

BrightPowder - This item can reduce an opponent's Accuracy by up to 7.8%, but is again limited to certain attacks, which are listed out in the GSC Attack Attribute list. Can only be received in Trades.

Focus Band - Even when the Pokemon is on a respirator, there's an 11.7% chance of having 1 HP leftover no matter what the attack. For status changes that hurt you every turn, attacks like Destiny Bond and Perish Song, or if you use Self-Destruct or Explosion, the item will not help you. Can be gotten in Saffron City.

Scope Lens - This increases the Critical Hit rate by 12.5%. Can only be gotten in Mystery Gifts and in a "In-Game" gift.

Stick (Farfetch'd only) & Lucky Punch (Chansey only) - Sets Critical Hit rate at 25%. Can only find Sticks on Wild Pokemon and Lucky Punch in Trades.

Light Ball & Thick Club - Light Ball is exclusive to Pikachu and raises its Special Attack * 2. Also, the Thick Club only works with Cubone and Marowak, and doubles their Attack. However, if Pikachu's Special Attack or Cubone/Marowak's Attack go above 1024, the item backfires (Attack/Special Attack become 0 or near there). Light Balls can only be gotten in trades, and Thick Clubs can only be gotten in Wild battles.

MetalPowder - Only works on Ditto, this item raises its Defense and Special Defense * 1.5. Can only be gotten in Trades.

Leftovers - Each turn, it recovers 1/16 of the attached Pokemon's Maximum HP. Can be gotten in Celadon City, or they are always attached to Snorlax's, whether caught or traded.