Negative levels and experience gain

[Conradine]

If a PC wear / use an item that constantly bestow upon him one or more negative levels, but those level are never permanent ( like a good character using an Unholy weapon ) , is the PC considered lower level for XP gains, or nothing changes?

[sleepyphoenixx]

Negative levels have the effects described in the condition summary. They don't affect XP calculation.

[Rijan_Sai]

Just be aware that even non-permanent Negative Levels can kill you if they exceed your HD.