Monsters use the Monster base class, which is define in Data/Scripts/ You can find the game’s monster classes scripts inside Data/Scripts/Monsters/.

Monster States

Monster behavior can be in one of the following states:


The monster will do a line of sight check for the player in front of it. If it has line of sight it will target the player.

When idle monsters can also “hear” the player and spot him, using the function hearSound. Monsters can also be set to be deaf with the variable deaf.


The monster will move in random direction baised towards its target. When it has line of sight on its target it has a random chance to start an attack that increases as it gets closer to its target.

Additionally when the monster starts moving, if it’s within instant_attack_range distance from the target, it will instantly start an attack.


The monster will target either the player or whoever damages it. Monsters of the same type can’t damage each other. If the monster doesn’t have line of sight of its target for long enough, it will go back to idle state.

After its target dies the monster will go back to idle state, unless it already spotted the player, in which case it will target the player.

The function choose_attack is used to select which attack the monster will use (for example melee or ranged). Inside the function you can set several options:

  • continue_attacking is used to tell the monster if to immediately start another attack after this attack ends if true, or start moving if false.
  • cancel_attack is used to cancel the attack by setting it to true.

When the monster starts attacking it will play its attack animation. Animation trigger can be used to decide when to execute attack_callback with trigger value "attack", and when to end the attack with trigger value "end". If you use animation trigger you must set attack_callback inside choose_attack. attack_callback is a ATTACK_CALLBACK funcdef.

Alternatively you can set use_attack_duration to true and set attack_duration to how long the attack should last. This approach doesn’t use attack_callback. Instead you can override attack_update which will be called every fixed update while attacking.

attack_end is called when the attack ends.

You can use things from Attacks for your monster attacks.


Flinching will interrupt the monster’s movement and attack. When the flinch ends the monster will start moving.

When a monster takes damage, it has a chance to flinch. flinch_chance is the chance variable, and its value should be in the range [0,1].

Flinching lasts for the duration set in MonsterType::flinch_duration.

Creating new monsters

Existing behavior

You can create new variation of an existing monster by copying its node object and editing its properties. can use the game editor for that. The game’s monster node object files are inside Data/Objects/Monster/.

New behavior

You can create new monster behavior


MonsterType holds information that is the same across all instances of the monster class, for example animations and sounds.

You need to create a new MonsterType instance using the function game.levelInfo.add_monster_type and set its variables. The game does that for its monsters inside a function, and calls all those monster type functions in the function RegisterMonsters which is defined in Data/Scripts/ and called when the level starts.


Derive your new monster class from Monster. MonsterFly is also available.

In your class’s constructor set Monster::type to your MonsterType using the function game.levelInfo.get_monster_type.

From here you’re free to do anything. Look at the game’s monster scripts for examples of how monsters can be implemented.