Moat Door Skip

Moat Door Skip is a technique which uses Parallel Universe navigation to reach the door in the castle moat without lowering the water from inside. This is done in the 1 Key TAS to beat the game without collecting the basement key from Bowser in the Dark World. Normally, Mario cannot open doors underwater. To open a door, Mario must be in either the walking action or the deceleration action, neither of which are obtainable underwater. However, the door is still functional underwater and, if Mario can get directly to the door without going underwater, there is a 1-frame window where Mario can open the door before the water takes action. Since water is not loaded in PUs, careful PU movement allows Mario to get to the door without going underwater and open it. The PU movement requires a substantial amount of speed, and there are two methods for hyperspeed that can be used for moat door skip; Hyperspeed Walking and Elevator BLJs.

Hyperspeed Walking

Doing Moat Door Skip with hyperspeed walking requires Mario to build up about 643 thousand speed, taking around 100 minutes. The speed is used to put Mario 2 PUs to the left, then 20 PUs to the right, then 14 PUs to the left, then another 4 PUs to the left, allowing him to access the moat door early.

Backwards Long Jumps

Doing Moat Door Skip with BLJs requires an elevator, as regular BLJs in the castle grounds do not offer enough speed for the necessary PU movement. The elevator used is one in Vanish Cap Under the Moat, which Mario can clip into early with precise BLJ movement. After gaining the necessary speed in VCUTM, Mario can then void out and conserve the speed into the castle moat. From here, Mario swims to the ground, and then uses the reactivated stored speed to do the PU movement to enter the moat door.

Use in Challenges

Moat Door Skip can be used in the low B-Button challenge to skip a B-press required in Bowser in the Dark World. Although it is possible to do Moat Door Skip in 0 A-presses with Hyperspeed Walking, this is currently not required to save an A-press, nor does it save time in any current strategy.