Character AI in GTA 2 Mission Scripts

You have a lot more control over mission characters in GTA 2 than in GTA 1.

Occupations

This details what they do, from criminal to police officers. Below is a list of valid occupations for your peds.

Occupations
ANY_ELVIS Primarily used for bonus checks.
ANY_EMERGENCY_SERVICE_MAN
ANY_GANG_MEMBER
ANY_LAW_ENFORCEMENT
ARMY Army Soldier.
BANK_ROBBER Bank Robber.
CARTHIEF Dude who goes and steals cars.
CRIMINAL Normal Criminal.
CRIMINAL_TYPE1 Attacks CRIMINAL_TYPE2 characters.
CRIMINAL_TYPE2 Attacks CRIMINAL_TYPE1 characters.
DRIVER Driver of a car.
DRONE Probably follow exactly what you do.
DUMMY Normal ped.
ELVIS Part of an Elvis group.
ELVIS_LEADER The leader of an Elvis group.
FBI FBI bloke.
FIREMAN Fireman.
GUARD Guards an object or area.
GUARD_AGAINST_PLAYER Guards against the player.
MUGGER Steals peoples cash and runs away.
NO_OCCUPATION Used for START_BONUS checks.
POLICE Police Officer.
PSYCHO Goes around city killing people.
REFUGEES Probably have no weapons, weak etc.
ROAD_BLOCK_TANK_MAN Dude at Tank road block.
SPECIAL_GROUP_MEMBER Probably someone who can fight independantly of the player.
STAND_STILL_BLOKE Someone who stands very still.
SWAT SWAT member.
TANK_DRIVER Driver of a tank.

If you want to make your peds to act as a guard, you’ll need to make them know who to look out for. By default, if a gun is fired when he is on screen, he will simply run away and then return. You need to use the THREAT_SEARCH as well as THREAT_REACTION (next topic) in order for him to effectively act as a guard:

SET_CHAR_THREAT_SEARCH (name, SEARCH_TYPE)
Values for SEARCH_TYPE
NO_THREATSDoesn’t look for threats.
LINE_OF_SIGHT90° search area. Blocked by buildings but not cars and objects.
LINE_OF_SIGHT_PLAYER_ONLYSame as LINE_OF_SIGHT except only the player is looked for.
AREAAbout 3 cells in every direction. Moves with the character.
AREA_PLAYER_ONLYSame as above, but only looks for the player.

Example code:

SET_CHAR_THREAT_SEARCH (guard01, LINE_OF_SIGHT_PLAYER_ONLY)

Now that your character has found the player, what does he do? Stand and fight or run away? This where reactions come into it. The next topic details this.

Threat Reaction

The THREAT_REACTION makes you choose what the ped does when he finds a threat, he can either react as normal (such as shoot) or run away.

SET_CHAR_THREAT_REACTION (name, REACTION_TYPE)
Values for REACTION_TYPE
NO_REACTIONIgnores the threat.
REACT_AS_NORMALDo the default for that occupation. A guard will attack the threat.
RUN_AWAYOnce the character is far away from the threat, it will to normal action.

Example code:

SET_CHAR_THREAT_REACTION (guard01, REACT_AS_NORMAL)

Objectives

You can also give objectives to the ped to make him do a number of things, from shoot a person, get in a vehicle, walk to location and many more. If the character is told to walk to a location, he will do that objective until he gets there and then he stops waiting for another command, so this is where IF commands come into it, but for now we’ll just detail the one-off objectives.

SET_CHAR_OBJECTIVE (name, OBJECTIVE_TYPE)

This is a basic function which tells him to do this:

SET_CHAR_OBJECTIVE (name, OBJECTIVE_TYPE, second_item)

This is generally used for "kill this" actions or entering/exiting cars. The second item is a previously created car, character or something else. The game will crash if the object doesn’t already exist when you use this command!

Can also be used for "go to" commands if you put an (X,Y,Z) coordinate in:

SET_CHAR_OBJECTIVE (name, OBJECTIVE_TYPE, X,Y,Z)
Values for OBJECTIVE_TYPE (without second_item or coordinates)
NO_OBJMake him walk around like a normal ped. Useful if you don’t need the character anymore.
WAIT_ON_FOOTWait on foot until something happens. Simple.
FLEE_ON_FOOT_TILL_SAFECharacter runs away until he thinks he’s safe, about 6 blocks.
GUARD_SPOTGuard his standing position. Best give him a weapon.
GUARD_AREAGuard this area, usually 3–6 blocks.
WAIT_IN_CARSits inside a car doing nothing.
Values for OBJECTIVE_TYPE (with second_item)
KILL_CHAR_ON_FOOTCharacter runs after person on foot. Give him a weapon otherwise he’ll start punching him.
KILL_CHAR_ANY_MEANSIf he is off screen, he will use a car to chase victim. Will also warp so don’t put an arrow on him.
FLEE_CHAR_ON_FOOT_TILL_SAFERun away until he feels safe. Give him another command or he’ll start walking around normally.
FLEE_CHAR_ON_FOOT_ALWAYSAlways run away from this character.
GOTO_CHAR_ON_FOOTLocate a second character. Once done, it is classed as “passed objective” and will do nothing else.
LEAVE_CARExits a created car, must be inside car!
ENTER_CAR_AS_PASSENGEREnter a created car as a passenger.
ENTER_CAR_AS_DRIVEREnter a created car as a driver.
FOLLOW_CAR_IN_CARCharacter must be in a car to follow. Set the second item to be a previously created car.
FIRE_AT_OBJECT_FROM_VEHICLECharacter must be inside to work, useful for tanks.
DESTROY_OBJECTSet the second item to what is going to be destroyed.
DESTROY_CARDestroy a previously created car.
Values for OBJECTIVE_TYPE (with coordinates)
GOTO_AREA_ON_FOOTRun to a spot on the map.
GOTO_AREA_IN_CARDrive to a location on the map. Must be inside car when you use this command!

FOLLOW_CAR_ON_FOOT_WITH_OFFSET

This requires a second_item, an integer rotation, and a floating point distance. Remember to limit the driver’s maximum speed so the characters can stay with it! Also remember you might need bigger distances for bigger cars when they turn, such as the Limosine.

SET_CHARACTER_OBJECTIVE (name, FOLLOW_CAR_ON_FOOT_WITH_OFFSET, second_item, rotation,distance)

Example, following about 1 block away to the left:

SET_CHARACTER_OBJECTIVE (bodyguard, FOLLOW_CAR_ON_FOOT_WITH_OFFSET, presidential_limo, 270,1.5)

Example, leading the car by a few blocks (might fall behind when the car turns):

SET_CHARACTER_OBJECTIVE (bodyguard, FOLLOW_CAR_ON_FOOT_WITH_OFFSET, presidential_limo, 000,4.0)
FOLLOW_CAR_ON_FOOT_WITH_OFFSET Orders the character to follow the movements of a particular car 'on foot'. distance is measured from the centre of the car. rotation sets which side of the car. second_item is the name of the car to follow.

Examples

SET_CHAR_OBJECTIVE (guard01, GUARD_SPOT)
SET_CHAR_OBJECTIVE (guard02, GOTO_AREA_ON_FOOT, 12.5,27.5,2.0)

Patrol Points

You can simply leave guards and others just stand on the spot, but you can also add patrol points for them and add as many as you like!

ADD_PATROL_POINT (name, X,Y,Z)

The guy will walk to it, and back to his original place, and then back again for infinity until you tell him to do something else. An example could be:

ADD_PATROL_POINT (guard02, 12.5,13.5,2.0)

You don’t have to tell him to return to his start position as he’ll do it automatically. If you’re just making him go back and forth, you just need to add one patrol point set to the location to walk to.

(Originally written by Chris “Pyro” Hockley and formatted by Ben “Cerbera” Millard with full permission.)