hey guys, i wanna ask are flames if be used ingame will cause a lag game?

Not all flames cause lags. Big, fast and multiple flames are the ones usually causes lag in the game.
If you happen to experience lags, you can simply type in the command /opt particles 0 to remove the flame. You can set it back by typing /opt particles 1.

oh k,thanks KZero

or /opt particles without the 0...

Flame make you lagg cuz they are too particles , and they move too fasts , or they are too big . Some video cards don't support Particles , like Flames or Shaders .