Make player non-existent to specific player

Hello,

I started to study UE4, with Udemy’s course, and I have a question.

I want to make a little game prototype, with an “uncommon” mechanic. Let me explain.

For example, the round start with 4 players, noted player 1, 2, 3 and 4.
At some point, on a specific action, player 1 and player 2 will not be able to see each other anymore.

Player 1 still see player 3 and 4.

Player 2 still see player 3 and 4.

Player 3 still see player 1, 2 and 4.

Player 4 still see player 1, 2 and 3.

And by don’t “see” it anymore, I also mean, no interaction at all. Player 1 and 2 are invisible, and can’t collide themselves.

Where do I need to look to find the proper knowledge ? Is it a matter of replication ? Conditional replication ? Relevancy ? Just a matter of “hidden” and “collision” property ?

The only thing I’m (almost) sure is I have to keep an array of “players visibility” in the GameMode class.

Thanks in advance.

It’s my first question on this forum and on UE4, I hope it’s not stupid.