The land moves

The ground is not still. The planet fights back with it.

• A boss's heavy blow cracks the ground. When a warden, a zone boss or a Castellan brings down a move that reaches everyone round it, a crater sinks into the ground where it stands, with a low rim thrown up round it. Fight on its rim and you fight uphill.
• Quakes. Now and then, somewhere out in the open near a player, the ground heaves up and down across a few dozen metres and cracks open in two or three places. The chat says so. Where you stand drops or rises with it; a crack under your feet is a fall.
• Caves open. Half of all quakes split a hillside nearby into a new cave: a tunnel running into the hill at a gentle fall, roofed wherever the hill is thick enough and open to the sky where it is not. It is a cave like any other from then on: dark away from its mouth, walked on and under, and the minimap turns to a plan of it once you are inside.

What the world keeps, it keeps. Nothing moves the ground under water, under anything built, in a pass, in the city, round a graveyard, a dungeon's door, an outpost, a castle, a farm, a maze or a quarry.

Everyone in the zone sees the same change at once, and anyone arriving later finds it as it is.