See the Python reference of this logic brick in
The Message Sensor can be used to detect either text messages or property values. The sensor sends a positive pulse once an appropriate message is sent from anywhere in the engine. It can be set up to only send a pulse upon a message with a specific subject.
See Message Actuator for how to send messages.
See Sensor Common Options for common options.
- Specifies the message that must be received to trigger the sensor (this can be left blank).