Well, I'd use WPE Pro if the packets aren't timestamped or encrypted or whatever it is they do these days. Some games that store the hit data on another person require a packet from you to say you got hit (IE guy shoots you, your computer registers a hit, your computer sends a packet to whoever's hosting saying to decrease your health), in which case you could just make a filter. It might also be possible to use WPE Pro to send the "I picked up a health powerup (or this game's equivilant)" packet over and over to the host's computer, so you get healed ever 1/10 of a second, assuming that your computer determines whether you've picked up a health packet and not his. If it's an RPG type game, since you didn't give many details, you might be able to use cheatengine or something to up your defence to insane levels so you take no damage (if the damage processing is done on your comp and sent to his to modify your health, you could do this any time, but if you upload your defence then he calculates damage you'd have to have this hack running before you joined a room). It really depends on how the game's set up, and exactly how much IS done on your comp, so you could get a little more help if you posted up more details.