A simple request for a simple mod. What I want is simply a mod that does nothing else except lower the amount of experience points you get. I want to basically 100% the game in one playthrough and I know I hit the exp ceiling long before that in vanilla FO3, so the same thing will probably happen in New Vegas. Ideally, the mod would come with a few different options, maybe a choice between 75%, 50% or 25% the amount of experience. Something like that. Thanks a bunch

http://www.gamesas.com/index.php?/topic/1123423-relz-arwens-nv-realism-tweaks/ comes with an XP reducer feature. By default it sets it to a 75% reduction (so you get 25%) but it's customizable ingame.

I've seen that, but like I said, I don't want any changes to my game except less exp since I'm playing the game for the first time and want a completely vanilla experience (pun intended, hehe). So while Arwen's mod is undoubtedly very nice, I don't want to use it in my game.

Not exactly what you're after, but there's one http://www.newvegasnexus.com/downloads/file.php?id=34836 that increases the experience needed to gain a level by 70%, and another http://www.newvegasnexus.com/downloads/file.php?id=35178 that lets you choose between 1.5x, 2x, 2.5x and 3x more.

The second one is perfect, thanks!