(or XP): Awards given to characters representing improvements in abilities and kills through adventuring. DMs/GMs may also give out bonus XP for good role-playing. This is called RPXP. (D&D 1)
characters earn XPs as they adventure. Experience may be spent just like Building Points to buy new skills and abilities or improve old ones.
As characters become more experienced, they gain Experience Points, which are treated the same as Option Points in every respect. That is, they can be spent to gain advancements for the character.