Enemies can walk on non-fully densed combos.

you mean combo's that are not entirely solid.

Confirmed. I've seen this many times in HF. More often than not, it happens when enemies walk down onto a combo like that

This bug has been present for quite a while actually. ... as long as I've known ZC, actually.

Here's an ASCII Diagram:

[font=courier]XX
OO[/font]

If a combo resembles that, with an unwalkable upper half and a walkable lower half, it can ignore the unwalkable upper half and walk into the walkable lower half.

Enemies tend to stick to that grid anyway, so to them, they're just moving from one 16x16 spot on the grid to another. They don't need to worry about the unwalkability factor in such a case because they're fully permissible in walking into that walkable spot anyway. They've always been able to. Here, take this diagram for example:

[font=courier]
XXXXXXXXXXXXXX
XXOOOOOOOOOOXX
XXOOXXXXXXOOXX
XXOOXXXXXXOOXX
XXOOXXXXXXOOXX
XXOOOOOOOOOOXX
XXXXXXXXXXXXXX
XXOOXXXXXXOOXX
XXXXXXXXXXXXXX
XXOOOOOOOOOOXX
XXXXXXXXXXXXXX
[/font]

They would be able to walk everywhere that there is a white space. :shrug: Seriously, they would just walk right through the vertical spaces. I think they can walk up through them too.

This has been... incorrect for a long time. I tried to fix it a few times, but the code is hard to work with unless you take a lot of time to examine it. And, incidentally, I've come to realize that this was present in 1.84 anyway and was (if I'm right) set to match the way it is in Zelda 1. A good example of this is the Level 1 entrance. I think that the Octorok can actually walk vertically halfway on either side of the tree (maybe just one side, not sure), but can't walk horizontally onto the same space. Technically, enemies should either be completely blocked if any of the combo is solid or be allowed to walk upwards onto a combo if it is not solid on the bottom and the current combo is not solid on top. And they should be able to walk horizontally on a combo if it is nonsolid on the bottom. Basically, just like Link if he were forced onto 16x16 pixel snap points instead of 8x8. *shrug*

why not just make the enemies snap 8x8?

They currently snap 16x16 (except for a few rare exceptions). Changing them would not only break their Z1 authenticity but be hard to do for some of the enemies.

so is this going to be an unfixed bug? or is there a way to do it but you don't know how?

What DN said was this may look like a bug in many ways but it actually mimics the behavior that enemies have in Z1. So even though it looks odd, it's not a true bug everywhere.

Basically in ZC you shouldn't make barriers that are only 1/2 tile wide. And make sure that all your barriers are marked as solid the whole way through. Kinda an annoying restriction at first, but once you're aware of it it isn't that bad. Really you shouldn't be trying to make super-packed areas anyway.

I'm leaving this an unconfirmed as I'm not sure the current behavior is actually consistent with Z1 behavior. Once I check it (and maybe change it to match), I'll reclassify this bug and perhaps add a quest rule to make any partially solid combos completely solid to enemies.

What say zcAmazing, you're the resident inconsistency expert?
Bug or not? 😉

I have seen this before when I played "Isle of the Winds" in the Level A dungeon. Stalfos walked through the tile with the non-walk on top left and top right of tile.

I checked in the Original NES Legend of Zelda and... When I saw the entrance of Level 1, the screen with one Octorok, the Octorok was able to walk through the bottom part. When it went on the cave combo and turned left, it went through that part that Link cannot cross. I am not sure. I will have to re-check it out. If I actually see it in the Original NES, then it is not a bug.

Freedom, I will notify you then. (edit of post) Checking in Original NES...

EDIT: I did see Octorok go through the partially solid part in Original NES. The top right and bottom right of combo is solid. Link cannot pass, but the Octorok did. Not a bug.

It's the large trees.

EDIT: But not in ZC. The Octorok didn't turn left when on top of the cave combo. They ignore the combo with top right and bottom right solid. That is an issue.

Reminder to self to look at this bug soon.

Trying to fix this now would likely break things and be messy to boot. Going to Limbo until at least 2.60.