I let my cats play rough sometimes, but we have a few rules, and they
seem to understand them. For example, they know they can play really
rough if I am wearing my heavy duty gloves. They might occasionally
get me on the arm by accident, but for them it is an interactive toy
to attack the glove. Full teeth and kicker attack. My hands are
relatively safe, and they know they can't play the game when my hands
are bare.

I actually get hurt more when they are in the happy mood where they
decide to give a love bite. Jay Jay doesn't cut me when he bites, but
he bruised me a few times.

Maynard used to chew on me for fun which never hurt. If I had a jean
jacket or heavy sleeve on, then he would bite harder. He seemed pretty
good at knowing what would hurt and what wouldn't.

And they also know that I will not punish them for injuries. I may
stop the game or pull back, but I will never hit or punish them. I
don't mind an occasional  scratch.

Maynard never played rough with anybody else. He knew I was safe but
didn't trust anybody else to follow the same rules. Jay Jay will kick
hard with anybody who plays, but he won't bite or scratch. He is still
very cautious when playing with other people.

I did have one cat who was a biter, so I did not initiate this  game
with her. She would bite for any reason - playing, angry, even very
happy. We all knew she could be dangerous especially when purring and
appearing very happy. Fortunately, she didn't like new people, so they
were never in a position to get bitten.

That depends completely on the cat. Seriously - I had one cat that used
to love being swung around while in a bag big enough to hold him. I'd
swing it around, put the bag down and the cat would come out a little
shaky but then go right back into the bag and meow until I swung it
around some more.