having chess engines running while playing

I often analyze while waiting for an opponent. therefore my engine is running sometimes during the game (of course I don´t look at it during the game).

But what if by coincidence the opening I was analyzing matches what happens in the game? Whould that be a problem?

Running an engine in the background is a problem. If you analyze the same opening you are playing "by mistake" its a huge problem.

I think that you are on wrong way bro!

@lovlas actually I wanted to ask similar question, I play on ICCF correspondence chess so my engine is constantly analyzing my games there (usually straight for 10+ hours), so should I turn it off when playing here (as you may suspect positions that are analyzed there are 25+moves deep that can't appear in a human match)? I dunno if that's against the rules :O

@lovlas That circumstance isn't explained in the Terms of Service:
"ii) Artificially boosting your own or another user's rating is considered cheating and users involved will be banned on the administrators' discretion.

viii) User conduct is contextual, and different penalties may apply depending on the administrators' discretion. What determines good conduct may change at Lichess' discretion."

how about analyzing rook endings? The chance of getting the exact same position goes close to zero. Does that offer a problem?

@FredtheCrusher I have a suggestion. How about analyzing the rook endgame after the game is finished? That way you'll be 100% innocent.

but then I just have to wait for games doing nothing. That seems to me to be a waste of time

For me this is cheating

This is like those questions about what constitutes being unfaithful in a marriage :D