PvP D&D?

[Saruman]

Are there any rules for Player(s) versus Player(s) Dungeons & Dragons?
Thanks.

[Greenish]

For 3.0, 3.5, and PF, the standard rules apply. If you want something more balanced within 3.5 framework, look into Test of Spite (http://www.giantitp.com/forums/showthread.php?t=113644).

[Studoku]

There's nothing that causes the rules to somehow stop working if a player attacks another player. The normal combat rules would happen.

That doesn't mean it's a good idea. PvP in 3.5/pf between two equally powered characters often turns into rocket-tag. Whoever wins initiative will often win at low-mid levels. At high levels or with highly-optimized characters, whoever gets past whatever his opponent is immune to typically wins.