# Particle triggers

> Understand how the Particle System can use particle colliders to act as triggers.

The Built-in Particle System's [Triggers](/engine/6000.3/manual/visual-effects/particle-systems/particle-system-modules/part-sys-triggers-module.md) module allows you to access and modify particles based on their interaction with one or more Colliders in the Scene.

When you enable this module, the Particle System calls the [OnParticleTrigger()](/engine/6000.3/script-reference/unityengine/monobehaviour/onparticletrigger.md) callback on attached scripts, which you can use to access lists of particles depending on where they are in respect to the Colliders in the Scene.