I wrote this tutorial because many people don't realize that just because when they test something in single player it works, that doesn't mean that it will work properly in multiplayer. If you are using the onstarttouch output to activate something and the onendtouch output to deactivate it, it will work perfectly when you test it yourself, but when it is played in multiplayer it won't work correctly. The reason for this is simple, you can have as many people as you want enter the trigger area and it will activate the light or whatever it is you are activating, but all it takes is one of those players to leave the trigger area for the light (or whatever) to be turned off. There is a simple solution for this problem which I will now explain.

This tutorial assumes you have a basic understanding of entities and using the I/O system.

In this case, we will be activating a light when players enter the trigger area, but the same setup can be used for anything you wish to activate with a triggermultiple. First we need our light, our triggermultiple, and a mathcounter. Now name the mathcounter and the light. Now we will add three outputs to the trigger_multiple.

My output named OnStartTouch Target entities named Light01 Via this input TurnOn

My output named OnStartTouch Target entities named Counter01 Via this input Add With a parameter override of 1

My output named OnEndTouch Target entities named Counter01 Via this input Subtract With a parameter override of 1

Now when a player enters the trigger area the light will be activated and 1 will be added to the mathcounter. When the player leaves the trigger area 1 will be subtracted from the mathcounter. However, with the current setup, the light will not turn off. To set it up to turn off, we need to add an output to the math_counter so that when it reaches its minimum value the light is turned off.

My output named OnHitMin Target entities named Light01 Via this input TurnOff

If you have any questions please fell free to ask.