Enemy AI
From Chrono Compendium
Notes on Enemy AI are currently incomplete; eventually, data will be decoded and added into Temporal Flux for functionality. Enemy AI information will be updated as new stuff comes.
Offsets
Directly from Geiger's Offsets.txt ___________________________________________________________________ 0C8B08 0C8D07 PTR No No Pointers to Enemy AI (local) 6/21/2004 0C8D08 0CCBC8 AI No No Enemy AI 7/14/2003 ___________________________________________________________________
Summary
Enemy AI is divided into two blocks that terminate with FF.
AAAAAAAAFF BBBBBBBBFF
The first block contains actions that the enemy performs on its own. The second block contains reactions when the enemy is attacked.
Each block can be broken down into sections that alternate between Condition and Action.
Condition
Conditions are a multiple of 4 bytes, each of which is a boolean statement. All must be true for the following Action section to be executed. The section is terminated by $FE.
Action
Actions can contain one or more commands to perform. An enemy's attack meter must refill first before it can continue with the next command. The section is terminated by $FE.
Conditions
There is a total of 41 Conditions ($00-28)
00 ?? ?? ?? nothing. continue with following Action 01 hh ?? ?? check health. hh - 03=50% 02 ?? ?? ?? 03 ?? mm ?? unknown. mm - monster index 04 ?? mm ?? check if monster is alive. mm - monster index 05 nn ?? ?? check number of enemies. nn - minimum? number of enemies that must exist for the following Action to be executed 06 ?? ?? ?? 07 nn ?? ?? check times attacked. nn - number of times the enemy must be attacked for the following Action section to be executed 08 ?? ?? ?? 09 ?? ?? ?? 0A ?? ?? ?? 0B ?? ?? ?? 0C ?? ?? ?? 0D ?? ?? ?? 0E ?? ?? ?? 0F ?? ?? ?? 10 ?? ?? ?? (only used once for Enemy $F8 R Series?) 11 ?? ?? ?? 12 ?? tt ?? if hit with tech. tt - tech index 13 ?? ?? ?? 14 ?? ?? ?? 15 ee ?? ?? if hit by attack. ee - 80=lightning 16 ?? ?? ?? (possibly unused) 17 cc ?? ?? load random number. cc - chance to execute following Action 18 ii ?? ?? if hit by specific weapon. ii - weapon index 19 ?? ?? ?? 1A mm nn ?? if number monsters alive?? -- mm monster index, nn number needed to be alive 1B nn ?? ?? if num pc's (alive?) -- number of pc's 1C ?? ?? ?? 1D ?? ?? ?? 1E ?? ?? ?? 1F ?? ?? ?? check distance. 20 ?? ?? ?? check if defeated. 21 ?? ?? ?? 22 ?? ?? ?? 23 ?? ?? ?? (same as 18) 24 ?? ?? ?? (same as 18) 25 ?? ?? ?? (same as 18) 26 ?? ?? ?? (same as 18) 27 ?? ?? ?? (same as 18) 28 ?? ?? ?? (same as 18)
Older data not 100% confirmed:
05 XX 00 00 - number of enemies atleast XX 40 00 XX 01 - If monster XX is dead...byte 2/4 unexplored 09 00 00 00 - Physical Counter. 10 00 00 00 - Always Counter. 11 00 00 00 - Magical Counter. 15 XX 00 00 - Elemental Counter - 20 Ice, 10 Fire, 80 Lightning, 40 Shadow, 00 Physical. (02 and 04 have been used, only saw them skimming the listings) 1F 04 XX 00 - Is enemy distant (non-zero) or up close (zero)?
Actions
There is a total of 23 Actions ($00-16)
00 ?? ?? ?? wander mode. 01 aa ww ?? attack mode. aa - attack index ww - who to attack: 05 random pc 06 nearest pc 08 pc using unknown hp conditions 02 tt ww ?? ?? ss tech mode. tt - tech index ww - who to attack: 05 random pc 06 nearest pc 08 pc using unknown hp conditions ss - battle enemy message string 03 (nothing, no routines) 04 random action. uses a random number to determine which action in current section to start on. 05 ?? ?? unknown, possibly unused, and not confirmed if it is a 3 byte command. 06 (nothing, no routines) 07 mm aa hh become monster. mm - monster to turn into aa - animation? hh - hp 08 (nothing, no routines) 09 ?? display flashes for distant attack? 0A aa ss run away. aa - action to show ss - battle enemy message string 0B oo vv mm ss set stat. oo - offset from enemy stat set start vv - value to set/bitwise OR mm - mode, 00 set value 01 bitwise OR ss - battle enemy message string 0C oo vv ss stat math. oo - offset from enemy stat set start vv - multipurpose byte, 80 subtract flag, 7F amount to add/sub ss - battle enemy message string 0D ?? ss unknown, state change? ss - battle enemy message string 0E (nothing, no routines) 0F ss display text. ss - battle enemy message string 10 vv ee ss revive support enemies. vv - unk. stored to temp 7E000E ee - battle sound effect ss - battle enemy message string 11 oo vv oo vv oo vv oo vv ss multi stat set. oo - offset from enemy stat set start vv - value to set ss - battle enemy message string 12 ?? ?? jj jj oo vv oo vv oo vv oo vv oo vv ss special multi stat set. jj - multipurpose byte, 80 copy flag: 7EAED8 to 7EAECC, 7F subroutine index oo - offset from enemy stat set start vv - value to set ss - battle enemy message string 13 jj vv unknown, possibly unused, and not confirmed if it is a 3 byte command. jj - multipurpose byte, 80 copy flag: 7EAED8 to 7EAECC, 7F subroutine index vv - unknown value stored to temp 7E000E 14 oo vv oo vv oo vv oo vv ss multi stat math. oo - offset from enemy stat set start vv - multipurpose byte, 80 subtract flag, 7F amount to add/sub ss - battle enemy message string 15 ?? ?? jj jj oo vv oo vv oo vv oo vv oo vv ss special multi stat math. jj - multipurpose byte, 80 copy flag: 7EAED8 to 7EAECC, 7F subroutine index oo - offset from enemy stat set start vv - multipurpose byte, 80 subtract flag, 7F amount to add/sub ss - battle enemy message string 16 -- tt oo vv oo vv oo vv oo vv ss multi revive and set stat. tt - tech/tech animation related index oo - offset from enemy stat set start vv - value to set ss - battle enemy message string
Older data not 100% confirmed:
00 WW XX YY - wander mode YY is how you wander, WW animation related? 02 WW 05 XX YY ZZ - Spell WW, Message ZZ, XX YY for double/triple?
Supplemental Material
From: Offsets (Chrono Trigger)
