Emerald AI guide

TABLE OF CONTENTS
I. Basic AI principles
II. AI by fight
III. Notes by fight

NOTE: Emerald's code has been only partially disassembled, so this guide is based mostly on observations and may not be 100% accurate.

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I. BASIC AI PRINCIPLES
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- There are many AI clauses. Which clauses are in effect depends on trainer class, but given our current knowledge, it's easiest to simplify trainers as having "good AI" or "bad AI"
- Characteristics of good AI (some exceptions apply):
	> Always try to OHKO if possible. This overrides most other decisions
	> Favor stat-increasing or stat-lowering moves when HP is above 70%
	> Choose most damaging move (e.g., Rock Throw over Tackle)
	> If multiple moves will kill, select one at random
	> If faster than the player (you), do not use a Speed-lowering move
	> "Ignore" fixed-damage moves such as Seismic Toss and Sonicboom (they can be used but are never encouraged or discouraged)
	> Discourage confusion moves when the player is at low HP (e.g., Supersonic, Confuse Ray)
	> Dismiss useless moves (e.g., Supersonic if already confused)
- Characteristics of bad AI:
	> Select a move at random
	> Dismiss useless moves in some cases, but not all
	> Do not calculate damage
- When calculating damage, the AI first "simulates" a roll. This is separate from the actual roll that occurs if the move is chosen. For example, if you have 13 HP and a trainer with good AI has one attacking move that does 12-15 damage, it will always choose that move if the simulated roll is 13, 14 or 15, but not necessarily if the simulated roll is 12.
- In double battles, the AI looks at both of your Pokemon before making a decision, unlike Sapphire. So for example, if Pokemon 1 is in kill range and Pokemon 2 isn't, it will always target Pokemon 1
- All wild Pokemon will choose a move at random under all circumstances

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II. AI BY FIGHT
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Rival 1			Good
Calvin			Bad
Grunt			Bad
Josh			Bad
Tommy			Bad
Marc			Bad
Roxanne			Good
Clark			Bad
Devan			Bad
Grunt			Bad
Grunt			Bad
Grunt			Bad
Pokefan			Bad
Pokefan			Bad
Rival 2			Good
Triathlete		Bad
Psychic			Bad
Youngster		Bad
Wally 1			Good
Ben				Bad
Wattson			Good
Hiker			Bad
Hiker			Bad
Aroma Lady		Bad
Grunt			Bad
Grunt			Bad
Tabitha			Bad
Maxie 1			Good
Flannery		Good
Brawly			Good
Cooltrainer		Good
Cooltrainer		Good
Cooltrainer		Good
Norman			Good
Grunt			Bad
Grunt			Bad
Grunt double	Bad
Shelly			Good
Rival 3			Good
Bird double		Bad
Bird Keeper		Good
Winona			Good
Grunt			Bad
Grunt			Bad
Grunt double	Bad
Grunt			Bad
Grunt			Bad
Grunt			Bad
Grunt			Bad
Grunt			Bad
Grunt double	Bad
Tabitha			Bad
Maxie 2			Bad
Grunt double	Bad
Grunt double	Bad
Matt			Good
Swimmer			Bad
Mossdeep double	Bad
Psychic			Bad
Hex Maniac		Bad
Psychic			Bad
Tate & Liza		Good
Grunt			Bad
Grunt			Bad
Grunt			Bad
Grunt			Bad
Grunt			Bad
True double		Good
Archie			Good
Juan			Good
Wally 2			Good
Cooltrainer		Good
Cooltrainer		Good
Cooltrainer		Good
Cooltrainer		Good
Cooltrainer		Good
Sidney			Good
Phoebe			Good
Glacia			Good
Drake			Good
Champion		Good

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III. NOTES BY FIGHT (not updated)
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These fights follow "good AI" rules unless otherwise noted.

RIVAL 1
- Seems to discourage Leer after turn 1, but can still use it
- Seems to never use Leer when you're below 70% HP
ROXANNE
- Favors Rock Tomb if Mudkip is faster; can't be used otherwise
- Favors Harden on turn 1
- Greatly favors Block on turn 2+ once your Speed has been lowered
- Favors Harden on the turn after you use Growl, Mud-Slap or Tackle (~75% likely if nothing else is favored)
POKEFANS (they only have partial "bad AI")
- All: 50% Growl, 50% QA
RIVAL 2
- Slugma: 50% Yawn, 50% Ember unless in kill range (even when asleep)
- Always uses QA if it kills
- Discourages Supersonic if your HP is 70% or less; dismisses it at 50% or less
WALLY
- Generally spams Double Team
WATTSON
- Voltorb: ~89% Rollout, ~11% Selfdestruct
- Favors Howl on turn 1
- Seems to discourage Howl after turn 1, but can still use it
- Discourages Supersonic if your HP is 70% or less; dismisses it at 50% or less
MAXIE 1
- Discourages Sand-Attack if your HP is 70% or less
FLANNERY
- Slugma: ~40% Smog, ~30% Light Screen, ~30% Sunny Day
- Slugma: Cannot use Light Screen if it has 50% HP or less
- Slugma: Cannot use Sunny Day if it has 40% HP or less
- Dismisses Overheat unless it can kill
- Torkoal: ~60% Body Slam, ~40% Attract
RANDALL
- 100% Wing Attack
PARKER
- 33% Focus Punch, 33% Dizzy Punch, 33% Teeter Dance
- Does not discourage Teeter Dance when confused
JODY
- On turn 1: ~80% Swords Dance, ~20% Slash
- On turn 2+ ~40% Swords Dance, ~60% Slash
MARY
- 100% Faint Attack
GEORGE
- At full HP: 50% Counter, 50% Shadow Ball
- Favors Slack Off at low HP
BERKE
- ~70% Slash, 30% Focus Energy
NORMAN
- Spinda: 50% Facade, 50% Teeter Dance
- Does not discourage Teeter Dance when confused
- Never uses Encore
- Discourages Belly Drum
- Encourages Counter
- Discourages Yawn
- Does not dismiss Yawn if you are asleep
SHELLY
- Encourages Swagger if your HP is high
- Discourages Swagger if your HP is low
RIVAL 3
- Encourages Harden and Amnesia on turn 1
- Pelipper: 100% Protect turn 1
- Discourages Supersonic if your HP is 70% or less; dismisses it at 50% or less
WINONA
- Swablu: ~50% Mirror Move, 17% Safeguard, 17% Aerial Ace, 17% Perish Song
- Always switches out Swablu on the last turn of Perish Song
- Pelipper: ~90% Protect, 10% Supersonic turn 1 when you are at half HP
- Pelipper: ~100% Protect if your HP is low (somewhere around 30%)
- Skarmory: Discourages Sand-Attack if your HP is 70% or less
- Favors Dragon Dance on turn 1
MAXIE 2
- Favors Scary Face
- Encourages Swagger if your HP is high
- Discourages/dismisses Swagger if your HP is low/lower
- Dismisses Confuse Ray if your HP is 50% or less
TATE & LIZA
- Claydol: Always uses EQ if one of your Pokemon dies to it
- Xatu: Favors Calm Mind on turn 1
- Dismisses Confuse Ray if your HP is 50% or less
TRUE DOUBLE
- Favors Scary Face
- Encourages Swagger if your HP is high
- Discourages/dismisses Swagger if your HP is low/lower
- Discourages Taunt
- Favors Amnesia on turn 1
- Crobat: Seems to favor Mean Look
- Dismisses Confuse Ray if your HP is 50% or less
ARCHIE 2
- Favors Scary Face
- Encourages Swagger if your HP is high
- Discourages/dismisses Swagger if your HP is low/lower
- Dismisses Confuse Ray if your HP is 50% or less
JUAN
- Favors Amnesia on turn 1
WALLY
- Favors Dragon Dance on turn 1
SIDNEY
- Discourages Sand-Attack if your HP is 70% or less
- Absol: Favors Swords Dance on turn 1
PHOEBE
- First Dusclops: 100% Protect turn 1
- Dismisses Confuse Ray if your HP is 50% or less
GLACIA
- Favors Hail
DRAKE
- Shelgon: 75% Protect, 25% Rock Tomb on turn 1
STEVEN
- Wailord: Favors Blizzard
- Gyarados: Favors Dragon Dance on turn 1