Level 0 is the repeating interior environment used for exploration, navigation, survival, and encounters. Its generated spaces are connected through authoritative routes and world layers rather than a single static map.
Navigation
Use landmarks, communicate turns, and preserve enough supplies to return to a known route. Generated spaces can make memorising a single fixed map unreliable; the same-looking corridor is not proof that you are near the last landmark. Search spots, doors, shafts, safe rooms, and active portals are resolved by the current shard.
Level 0 can contain hostile Mimic encounters, resource pressure, and route changes. Keep a retreat plan before entering an unfamiliar branch.