Note: Aware that max teabag has already made a video, but I feel like some guides are better written.
Have a timer that executes a trigger.
Trigger A
Trigger action 1: Set value of variable 'A' to slot of current player
Param A: ~currentPlayer
Param B: N/A
Every player has a slot number. The first player has a slot number of 0 (in base maps 1st player are god), the second player has a slot number of 1, 3rd player = slot 2, 4th player = slot 3 etc..
After running this trigger action, every player will store a **different** value in ~currentPlayer
For Player 1 : ~currentPlayer will equal 0
For Player 2 : ~currentPlayer will equal 1
For Player 3 : ~currentPlayer will equal 2
and so on...
Assume there's a USE button which will execute a trigger to show text. Our goal is to limit the trigger to only show text to the person who only press the button.
Trigger B
Trigger action 1: Set variable 'A' to player initiator slot
Param A: ~playerInitiated
Param B: N/A
For example, if player 4 presses the button, the variable will contain 3.
In every player's screen, they all saw player 4 pressing the button, therefore every player also store 3 in ~playerInitiated.
Trigger action 2: Continue trigger execution if only variable 'A' is equal to variable 'B'
Param A: ~playerInitiated
Param B: ~currentPlayer
The first trigger action will set the variable ~playerInitiated to whoever presses the button.
Then, the 'IF' trigger action will compare whether ~playerInitiated is equal to ~currentPlayer.
Remember, every client has 3 in ~playerInitiated but has a different value in ~currentPlayer.
Therefore, the text trigger action will only run with player 4 (he is the only player with 3 in ~currentPlayer).
Trigger action 3: Show Text 'A'
Param A: Only you can see this
Param B: N/A
Good luck.