it depends on the addon, trp2 was my favorite. RP can be done wonderfully with out add ons but some just make it more immersive like gryphonheart would let you make your own items so if you are RPing that you found a strange gem..instead of just typing it in text you can make an item, give it a name, description, stats, etc and link it or give it to other people. TRP2 would let you make and trade items, create quests, mail/trade items, create stashes around the world, and you could make your tooltip display more information for others to see like full name, custom class, IC/OOC description so if you had a broken arm before you wouldnt even need to type anything someone could mouse over your toon and see "oh hey that person looks injuried" So addons are not needed to RP but can make the RP experience more indepth but I personally dont feel the main purpose of RPing is to play the game with out addons. Just my opinion though :) I ran a heavy RP guild for years and I recomended members get some addons but if they choose to play with out them they were still more then welcome.