I don't really know of any specific forum to post in, so I figure I'd just pose the question in multiple areas. I want to play an open-world (meaning I can explore at my discretion, generally) game where I can construct structures and increase my abilities (rpg element, basically). Minecraft is too aimless and doesn't really have the ability segment that I'd want, so that's not really what I'm looking for (it's certainly close in some aspects though). - I'm looking for a feeling of being able to go wherever I want to, but also leaving my mark in an area and improving myself as I play.
You can try Dungeons (this is like dungeon keeper - but newer). The Sims Medieval is sims with RPG elements in it but it is not as open world as you'd like. Dungeons would pretty much keep your curiosity sated though.
DayZ comes close. Gigantic game worlds. You can build barricades and camp sites and such. No rpg elements, but the game keeps track of several statistics, including blood pressure, temperature and diseases. Current version is a free mod for Arma 2, but in a couple of months a standalone version will be available in stores. Among many additional features, it will expand on 'base building'.
