That's an interesting question. I thought that BG1 incorporated 2nd ed. rules, but it does not give additional experience for finding/disarming traps, unlocking things. BG2 does give exp for these actions, but I thought that BG2 used 2nd ed. rules also. I believe IWD1 used 2nd ed. rules, but you don't get additional exp for traps/locks. (Hey, I'm an old 1st ed. guy, so I don't know boo about 2nd ed. or 3rd ed.) I think I'll just go crawl into a hole for a while; my brain hurts.