The Manual › Under the Hood

The Unbound Engine

The game master for invented worlds: anything is possible, but only within the laws the world's creator set.

The Unbound Engine runs Unbound worlds: fantasy, science fiction, horror, prehistory, anything a creator can imagine. You build them with Craft Your Own World & the Community.

Anything goes, within the world's laws

Every Unbound world has its own world laws, set by its creator: whether magic works, how fast ships travel, what can and can't die. The engine treats those laws the way the Hourglass Engine treats history:

  • What counts as impossible is decided by the world's own rules, not by real-world physics.
  • If a story slowly drifts away from its genre, the engine names the problem and brings the scene back.

The same foundations

Everything else works as it does in the historical eras:

  • Your Ledger, inventory, goals and location are tracked every turn.
  • The Librarian writes cards for everyone you meet.
  • People have their own voices, wants and lines they won't cross. See How People Behave.
  • There are no easy wins, and your character can die.

Your secret

Your character's secret matters here. Expect the story to bring the threat of exposure closer from time to time.

As the creator, you can change a world's laws mid-game with Timekeeper Mode.

See also

Last updated 2026-10-08