It's B/X, LotFP. The only house rules we've done are no 6 page first level summoning spell (I think he said he was going to replace it with find familiar which is not in this version of the game but I never rolled it) and instead of one random roll for a levelup spell, I roll five times and choose one, which is good, because some of the spells aren't very useful and some of them I have already (or theoretically I could roll the same number twice which has not happened) so sometimes I wind up choosing between two spells.
This game is very hard on wizards but better with clerics although for them, turn undead is the first level spell. Yeah, I know that MUs being able to wear leather armor and clerics being able to use weapons that are not blunt, are not in the original basic. Clerics can only use one handed weapons because they need to have their holy symbol in one hand in LotFP
