UNUSUAL CONCEPTS IN RPGS

Whether it be a game mechanic or an additional subject such as a mini-game or optional dungeon puzzle, what are some things that you have tried or plan to implement in your games that are a bit out-of-the-ordinary to the realm of RPGs?

Myself? I've successfully implemented a tag mini-game to one of my projects, but something I've been throwing around for a while now is a way for players to purchase and expand on their own property à la Animal Crossing. The most efficient way to obtain furniture would be to craft if yourself from misc items such as wood and nails, though there will most likely be a merchant or two who would sell you furniture if you're looking for a quick way to decorate your abode. So far, I've been able to establish a crude yet effective means of creating such a system, though it may become more complicated when furniture such as pianos are introduced.


So far, the plan is to make available an upstairs addition if I can come up with some sane reason for doing so. I've also been thinking of including a way to purchase your own dungeon, complete with random bosses and loot. There would be multiple dungeon types that you could buy, such as a volcano/ice/earth dungeon of the short/medium/long variety with easy/intermediate/hard boss types (this would also affect what random equipment/items they drop on death.)

EDIT: I should have mentioned this before, but this focuses more on Indie or RM* RPGs and may not necessarily hold ground with all RPGs released commercially.