Recently, one of my favorite upcoming RPGs,
Malevolence - The Shadow of Ahkranox, has created a
Kickstarter project. It's my favorite because of its intelligent usage of procedural generation for practically everything, ranging from terrain generation to town planning to quests. If you read their stuff, the way they do things is rather ingenious. The key element is the game's proprietary procedural generation method.
So this is the super-secret part, but I'll tell you a bit about it. Yes, The Sword of Ahkranox's in-game world is quite literally infinite. No, I'm not exaggerating. The engine makes use of a new type of procedural generation that I invented myself. No fractals, no Perlin noise, no blobs, no diamonds. Instead it makes use of a hyperbolic paraboloid generating seeds which are used to create the world in four dimensions. X, Y and Z co-ordinates as well as a time coefficient. Changes that the player makes to the world as they move through it are stored in a temporary database but are then reset after the player has given enough time and distance between them. So, if you empty a chest in one dungeon, then travel across the world, eventually that chest will re-fill, however, due to the time coefficient, the seed that generates the content of that chest will now be different, thus putting different content in that chest.
The AI of NPCs and monsters also follows this procedural generation, so people won't just sit in one spot, but will travel around the world while you play, depending on their role.
This generation accounts for almost everything in the game. Spell creation, item creation, weapon creation, potion creation, NPC dialogue system, even the spell effects that happen on the screen. Due to this, the world that the player explores will be ever-changing and infinite. They won't keep finding the same old weapons or items, there will be no end to the number of spells they can find or use, they won't even keep having the same conversations with NPCs.
"That's impossible!" I hear you cry. Well, it's already working fine. I know you're only seeing the dungeons at the moment, but that's because their pretty. The other parts of the game aren't pretty yet ;-)semi-technical explanation of procedural generation method by Malevolence developer and PR manager Alex Norton
Thankfully, this is all backed up by some excellent artwork and retro-inspired gameplay elements, so it's not going to end up like a fancy tech-demo (one could argue that the Crysis series of games would qualify as this).