Stepping down while sneaking allows falling off of blocks

well that renders the sneaking feature useless on slabs/stairs

Why would you need it on slabs or stairs? You can't fall more than 1 block.

Anon, I don't understand what you mean. You need it for the same reason you need it on any other block, so you can look over the edge without falling. And of course you can fall more than 1 block if there if more than a one block space below the spot where you fall off.

As far as I can tell, when the slab is on top of the block, which is one block above the ground, sneaking works fine. It is only sneaking off a slab that is 0.5 blocks off the ground where the sneaking doesn't work.

Have you thought about when you are making roofs for your houses and you are sneaking while descending down the stairs, and then you fall off. Fatal if it were a tall house

I was able to sneak down the roof, but not off of it. I don't see how that could cause damage.

That is exactly what I am talking about. The "half point" of the stair block is the point in which sneaking does not work.

But I can only seem to fall off stairs if there is NO drop.

(S = stair, A = air, B = block)

AA
AA
SA
BB
I CAN fall off here

AA
AA
SA
BA
BA
BA
BB
I CANNOT fall off here

AA
AA
SA
AA
AA
AA
BB
I CANNOT fall off here

Therefore, fall damage is impossible.

there are certain configurations whereby you can fall off roofs made of stairs/half slabs

Can you post a screenshot of one?

Duplicate of MC-2334?

I don't think it's a duplicate, but they are both already related. The underlying code may be the same for this bug.

Affects 1.6.2.

Affects 1.7.2. No longer an issue at the "half step" of the stairs. You can only fall when sneaking down the steps on the edge.

You know the purpose of sneaking is to avoid falling of edges. So this feature is still bugged

Maybe the player is not onGround for a short amount of time while "falling" from the upper stair to the lower stair and for that short moment the sneak function doesn't work anymore.

Still an issue. Photos added to illustrate. If you sneak directly toward the side of a stair you will not fall, but continue holding the sneak key and then move a half block down you will fall off the edge.

Yes thanks, that's what we found out in the meantime too.

Confirmed in 1.8-pre1

I believe this is more of a fundamentally quirky feature than a bug.

Sneaking only keeps you on top of a block if you're touching it. It also allows you to drop a small distance, which is exactly what you're doing when walking down stairs (or half slabs or the like). During the drop it doesn't do anything for you, so you can fall off at that time.

All of the potential fixes have significant side effects:

• Don't allow any drops at all.

• Hold the player back even if they're in mid-air.

• Glue the player to the ground on small drops.

• Add a special case.

The bottom line is that something will have to change in a big way. What do you want to break to fix this? I can't rule it out but it won't be pretty.

In short, what would be ugly about holding the player back in midair? I think that would be the best action taken, if any is.
Does MC look at blocks, the potential drop, or something else when deciding to keep a player from dropping? I imagine this would be easier to patch for the second option.

@unknown: The most basic extension would put you to a dead stop almost everywhere in mid-air. If you add a special case, the world is now permeated by invisible barriers, dwarfing invisible fence extensions. It plain makes no sense. If you add another special case to only make it work at very low speeds, descending while hiding from other players is still a much bigger pain than it already is. You can't win.

The movement algorithm iteratively checks whether your prospective bounding box has too much empty space below it. If so, it's slowly moved back to your previous position. Whoever coded it looks confused, but it looks like it should work in the end. Interaction with other adjustments might be responsible for those times when sneaking fails.

This is not actually a bug. What happens is that the game looks at where you are trying to fall to and sees that it is less than a block down, so it lets you fall. As you are falling, you move yourself slightly to the side with the movement keys, and you go off the edge of the stairs. This is no more a bug then the fact that lava kills you. If you don't want to fall off, don't walk towards the edge.

This is intended. It's your fault for moving yourself while falling. This report should be closed.

@unknown, it's already possible to float in mid-air, sneaking just makes it easier to get there. As shown in my screenshot, no part of my body is actually touching the stairs, and yet I'm considered standing on them. If you sneak straight towards the edge of the stairs, you cannot fall. The world is already "permeated by invisible barriers".

@unknown, your opinion has been noted, and there's no need to repeat it. If someone at Mojang directs us to close it, then we will. Or they can do it themselves. Or they can leave it open, or they can change the behavior. It's their decision to make, not yours.

@unknown: That's not really going anywhere. You can pull the entire game apart like that. Why don't you simply fall over, given the way your legs move? Right, because you only fall over when you die, moments before vanishing in a puff of smoke. Not that you'd normally see that in case of your own body because your arm (the only part of your body you can see in first person) disappears. Makes sense.

Simplified bounding volumes are much more reasonable than air barriers where you couldn't possibly grab something at any level. Sneaking basically activates simple AI that helps you not to fall off and shouldn't change physics drastically. So far the only deviation is that it makes you stop faster, at a point where you can usually stop almost as fast.

Okay, enough pedantry. There are relevant arguments up here somewhere. I have nothing to add.

Affects 15w51b.

Affects 16w02a.

Affects 16w04a.

Affects 16w05b.

Affects 16w06a.

Affects 16w07a.

Affects 16w07b.

Affects 1.9-pre1.

Affects 1.9-pre3.

Affects 1.9-pre4.

Affects 1.9.1-pre3.

Affects 1.9.2.

Affects 16w20a.

Confirmed for 16w42a

This is WAI.

If you while you are 'falling' down a step keep trying to walk off the side, you will move a bit in the air causing you to fall of the block.

Confirmed in 20w16a