How much of a strike is allowed in a tournament?

Iron palm to break grip for twister? Can I kick the shit out of a guy to escape his quater guard?

If by kicking you mean pushing his leg with your foot, that's fine

You are not allowed to strike at all. Pushing is legit. People do strike and make it appear as if they were trying to push. I consider it to be cheating. If people want to strike they should compete in vale tudo instead of submission grappling or Jiu-Jitsu.

people say "kick" but like JC said its realy a push your foot makes contact with there leg first then you "kick" as hard as you want. I hope that makes sense It does to me.

makes sense, thanks.

Great question, I've always found this to be a gray area. We need someone with lots of competition experience to give us a solid answer.

If you have to ask if you can do it then most likely you cannot do it. Ryu's Tatsumaki-Senpū kyaku is the exception of course. only if all the kicks land.