I have a cat who likes to play-fight with me - and she clearly knows it's just a game, because she is usually very gentle about it, never uses her claws and only nips my hand or fingers softly - it is actually really cute. At least, at first. Because sometimes, she seems to escalate herself into some kind of frenzy where although she still keeps her claws sheathed she will start biting harder and harder until it is really painful. And I can not even break off the fight easily, because even if I withdraw my hand and put it somewhere else, she keeps trying to get close and bite it - I really have to shoo her off (sometimes repeatedly) to get her to stop. I don't suppose there is a way to stop her from becoming so frenzied, but is there at least a way I can unilaterally stop the fight when I notice it is happening that restores the peace without actually having to scare her away? Or should I just stop play-fighting with her altogether? For some background, she is the only cat (and pet) in the household, about 5-6 years old, and a 100% indoor cat.
Stop play fighting with your hands. I work in the Cattery at an animal shelter. The first thing I tell people adopting a kitten --- "Never play rough with the kitten with your hands." It will teach the cat that it's ok to bite hands. It's cute when they're a kitten, not so much when they're older. Whether it was you or someone before you got your cat, this is what has happened. Since your cat is older, this is going to be a difficult behavior to stop. Thank you for loving your kitty and wanting to help her.
You will need to....
Only play with your cat with toys on the end of poles.
Limit your play sessions to only a few minutes at a time.
If she starts coming after your arm, give her a toy to redirect her attention and leave the room.
You will need to be consistent and patient. I wish you the best!
Stop playing the moment she crosses the line, say "hey! No!" or something like that, and walk away or otherwise not let her resume, so she has a clear indication of the limits. (Which is essentially what another cat would do.) She is capable of learning that claws and teeth have to be used more carefully on playmates, if you teach this properly.
Or stop wrestling before she becomes over-excited. You're the human; you're supposed to have better ability to predict consequences... <grin>