World Master
A RPG sandbox with huge procedural fantasy worlds. The World Master will generate unique lands for you to inhabit, explore, save, or destroy. Build your character from nothing, gain skills by using them, and affect the world by acting on dynamic objects in a vast sim.
The World Master is your simulated tabletop game master. They will build you a unique world, play as long as you like, will never tire of your antics, and will let you pursue any challenge you wish to take on. However, the World Master will not shelter you from the consequences of your actions or ill-preparedness.
The first step of generation produces random tectonic plates. From that moment forward the system is deterministic. Mountains form along faults, sunlight increases temperature, pressure drives the wind, rain flows into rivers and lakes and out to the oceans. Not dice rolls, physical laws.
Manage your resources wisely. Food, water, sleep, and equipment. It's relatively safe within a days walk of town, but out in the wilds, fresh water is scarce, food spoils quickly, and torches only keep small creatures at bay.
Humans settle across the world, but they aren't the only living creatures shaped by it. Monsters lurk wherever spears and armor don't reach, and sometimes even where it does.
These fantasy worlds are filled with monsters, and when you run into them, you will resolve your differences in turn based tactical combat. Spend your initiative to move and attack, but be careful, you need it to defend yourself as well.
Skills grow as you use them. Any time you use a skill to do something difficult, you gain experience points for the relevant skills and attributes. Adjacent skills are revealed, but nothing is stopping you from training skills you can't see on the web yet.