Mr Hobbit's Dungeon 2.15.5

• Flooded floors: the water flows now. It pours down the tunnel steps and spreads into the start room and the exit room. The exit pad itself stays dry: an invisible structure void sits over the pad, which water can't flow into but you walk straight through. Special rooms (fountain, shrines, vault and so on) are kept dry the same way, and a fountain keeps its own water. The tunnels and rooms are sealed, so the water can't escape. When the next floor is built, all the water goes with the old floor.

Mr Hobbit's Dungeon 2.15.4

• Silent floors never have stairs, even when a floor is made silent with /dungeon event silent (it used to keep the stairs it was built with). Every step is a block you have to jump.
• Silent floors' exit cage is sealed. The iron bars are now a ring one block out from the pad, 3 high, joined into a solid fence. Before, they were separate posts over the pad with gaps you could walk through. As a safety net, the exit pad doesn't work until the lever is pulled ("The exit is sealed. Find the lever.").
• Flooded floors: the stairs go. Each step becomes a full block with water on it, so staircases are runs of water steps (you jump up them, or swim). Rugs go too, with water in their place.

Mr Hobbit's Dungeon 2.15.3

• Tunnel roofs slope. Wherever a stair tunnel's roof steps up or down a block, the edge is an upside-down stair (across the full width, in the floor's own stone), so the roof follows the stairs instead of jutting out where a sprinting player would hit it.
• Tunnels are a block taller: 4 blocks of headroom, 5 where they climb. That's at least 3 clear blocks above every stair's top, even under the upside-down roof stairs, so you can sprint-jump up the stairs without bumping your head.
• Above the start room's doors the extra height is filled in solid, so there's no gap over the door frame.

Mr Hobbit's Dungeon 2.15.2

• Stair tunnels start further from the doorways. Every tunnel now has flat blocks at the room's level before its first stair: from the start room, the door, two flat blocks, then the stairs (the start room's door frame stopped you climbing a stair right behind it), and 2 flat blocks at other rooms.
• No more seeing out of the tunnels. Tunnel walls are one block thick, so the lantern niches had nothing behind them. Each niche now has rock behind it. On top of that, every floor gets a sealing pass after it's built: any open space next to a room or tunnel that isn't part of the dungeon becomes rock, so nothing looks out onto the void or into another part of the floor.
• /dungeon gentest also reports how much height the floors have. 100 test floors: all kept their heights (99 first time), an average of 6 blocks between the lowest and highest room, and 43 had 8 or more.

Mr Hobbit's Dungeon 2.15.1

• Stair tunnels: every step is now a full row of stairs across the whole 3-wide tunnel (on silent floors, a full row of jump-up blocks). In 2.15.0 the two side lanes took their height from the step behind the middle one, so only the middle lane got stairs and the sides were blocks to jump.
• Tunnel lanterns no longer hang from the roof where you'd walk into them on the way down. Each sits in a one-block niche cut into the side wall at head height, only where there's solid rock behind it. Room lanterns are unchanged.
• Headroom: every stair has at least 3 clear blocks above its top, so you never hit the roof walking down.

Mr Hobbit's Dungeon 2.15.0

• Much bigger height changes, built the way Ryan builds by hand. Whole rooms (floor, walls, ceiling and everything in them) now sit up to 8 blocks above or below the base level, so every room keeps its full height. Rooms other than the start and exit stay level 30% of the time and otherwise move 5 to 8 up or down. About one floor in five is gentle (at most 2 up or down). Rest floors and boss arenas stay flat.
• Corridors between rooms at different heights are enclosed stair tunnels, 3 wide. A flat block at each doorway, then one step per block, with a roof that follows the steps (4 blocks of headroom where they climb), and solid rock all around, so nothing opens onto the void. Where a corridor is too short for the difference, the rooms are moved closer in height. Monsters, baby zombies and the goblin use the stairs too.
• Silent floors: the same heights but no stairs. The tunnels are hop steps (one full block up per step), so going up means jumping every step, and every landing makes noise. Coming down is drops.
• Every floor is checked as it's built: a walk from the start must reach the exit pad and every room (one-block steps up, any drop). If a layout fails, it tries fresh heights (up to 4 times), then halved heights, and only then builds the floor flat. In a test of 100 random floors, 61 passed first time, 37 on a later try and 2 fell back to flat.
• Collapse floors: the pit sits below the lowest possible room. A fall into it from a high room can be 20+ blocks, so pit falls never do more than 3.5 hearts.
• Everything else follows the real heights: flooded water on each level, ambush bars at each doorway's level, sculk and soul lanterns on every level, dark floors put out lights at every height, and chests, spawns, special rooms, the lever and the goblin all use the room's real floor.
• For testing (ops only): /dungeon gentest <count> builds that many test floors far away and reports how many passed the walk check.