# Emission module reference

> Explore properties on the Emission module, to configure the rate and timing of particle emissions.

The properties in this module affect the rate and timing of [Particle System](/engine/6000.3/manual/visual-effects/particle-systems/class-particle-system.md) emissions.

## Properties

For some properties in this section, you can use different modes to set their value. For information on the modes you can use, refer to [Vary Particle System properties over time](/engine/6000.3/manual/visual-effects/particle-systems/varying-particle-system-properties-over-time.md.md).

| **Property**           | **Function**                                                                                                                                                                              |
| ---------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Rate over Time**     | The number of particles emitted per unit of time.                                                                                                                                         |
| **Rate over Distance** | The number of particles emitted per unit of distance moved.                                                                                                                               |
| **Bursts**             | A burst is an event which spawns particles. These settings allow particles to be emitted at specified times.                                                                              |
|     *Time*             | Set the time (in seconds, after the Particle System begins playing) at which to emit the burst.                                                                                           |
|     *Count*            | Set a value for the number of particles that may be emitted.                                                                                                                              |
|     *Cycles*           | Set a value for how many times to play the burst.                                                                                                                                         |
|     *Interval*         | Set a value for the time (in seconds) between when each cycle of the burst is triggered.                                                                                                  |
|     *Probability*      | Controls how likely it is that each burst event spawns particles. A higher value makes the system produce more particles, and a value of 1 guarantees that the system produces particles. |

## Additional resources

* [Particle emissions and emitters](/engine/6000.3/manual/visual-effects/particle-systems/configuring-particles/particle-emissions-emitters.md)