Affects Version/s: Minecraft 1.12.2, Minecraft 18w19a, Minecraft 1.13.2, Minecraft 19w08b, Minecraft 19w09a, Minecraft 1.14.3, 20w10a, 1.16.4, 20w46a, 20w51a
Fix Version/s: None
A player can only climb on a trapdoor if there is a ladder below. This does not work with any other climbable blocks which is inconsistent.
This is not related to the collision box of the ladder, see "Code analysis".
- Place any climbable block other than ladders (e.g. vines) below a trapdoor
Note: Blocks attached to the side, like vines, must be attached on the same side as the trapdoor
- Open the trapdoor and try to climb through it
You cannot climb through the trapdoor
20w10a, Mojang names
net.minecraft.world.entity.LivingEntity.trapdoorUsableAsLadder(BlockPos, BlockState) explicitly only checks if there is a ladder below the trapdoor and if that is the case treats the trapdoor as climbable.