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I'm having some trouble understanding ramps.

Taken from the Dwarf Fortress Wiki, concerning Movement Using Ramps:

For the purposes of unit movement, a ramp connects the ramp bottom to the tops of walls adjacent to the ramp bottom. So unlike stairs, where a dwarf moves directly up or down, a dwarf moving via a ramp will change both horizontal and vertical location in a single move. This can make it seem like a ramp has "direction" or "flow" by itself, but in fact this depends entirely on the spaces adjacent to the ramp.


More formally, for a creature to use a ramp, all of the following are necessary:

  1. The space directly above the ramp must be open.
  2. The ramp must have a wall next to it (including diagonals)
  3. The space above at least one of the adjacent walls must be open.

If these conditions are met, creatures will be able to move back and forth between the ramp space and the walkable space above the adjacent wall. Otherwise, the ramp will be labeled as "Unusable" when examined using the Look cursor.


Example A shows a situation where a ramp might be created that is actually unusable. Dwarves cannot ascend or descend (or cross) the ramp as shown because the walkable spaces above the ramp are not walled underneath, therefore dwarves cannot move between the ramp bottom and the spaces by the top of the ramp. If walls were added under the upper floor spaces, the ramp would become usable.

Note: Fortifications CAN be used by ramps as the adjacent 'wall', provided those fortifications have walkable space above them (which would apply to all carved out fortifications, or those constructed with additional flooring).


Finally, wagons follow a completely different set of movement rules on ramps. This can be exploited used to create separate paths for wagons and other (walking) creatures, for example to allow wagons to proceed directly to a depot while directing all other visitors through a trap filled maze.

This makes zero sense to me at all. i.e. there isn't a single part of the explanation that makes sense to me at all. What makes ramps usable in Dwarf Fortress?

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    It's hard to give an answer if you haven't made an effort to understand the mechanics involved. In short, ramps are usable if they lead to an open square above, if the ramp is supported by a wall on its backside. – Doktoro Reichard Aug 7 '15 at 17:18
  • I've been sitting here for the past half hour or so trying to figure it out. Does that count as an effort? – readyready15728 Aug 7 '15 at 17:19
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    It seems to lay out pretty clearly what 3 conditions are needed for a ramp to be a usable. What part do you not understand? – Son of a Sailor Aug 7 '15 at 17:30
  • What does it mean for a space to be "open"? Does that mean empty altogether? What do the dark red spaces in the diagram signify? How is it possible for a ramp at the edge of a corridor, which is what I have been doing, not to have a wall next to it? What are the "diagonals" in this case? – readyready15728 Aug 7 '15 at 17:37
  • Never mind, I think I finally figured it out. We'll see. – readyready15728 Aug 7 '15 at 17:58
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Ramps can be somewhat counter intuitive. Here is my understanding of how they work. A unit is standing in the ramp square. It is on the lower level. It has the option to move to one of the adjacent squares on the upper level, when all of these conditions hold:

  • The adjacent square is open (units can't walk into walls of course).
  • The square under the square that the unit wants to move to has a wall or a fortification in it.

Under certain circumstances you can have a ramp with the square above it blocked. A ramp in these circumstances is useless. (except for certain minecart exploits)

I have some ascii art side view diagrams of this. Let / be the ramp, _ be a square with a floor, but no wall, 0 be a square with a wall and floor, and an empty space be a square that is completely empty. A usable ramp looks something like this:

0000000 ____
_______/0000

Another example is this:

___ ___
___/000

When a dwarf is standing on the ramp square (the /) he can move up to the square just above and to the right in both of these cases and he cannot move into the square above and to the left.

Here are some broken ramps:

___ ___
___/___

Here the wall on the lower level is missing, so the ramp doesn't work.

___ 000
___/000

Here the upper level is blocked, so the dwarf can't get up the ramp.

Hopefully these examples help to clarify the situation.

  • This is more or less what I finally figured out (see below) and is the answer I will accept. – readyready15728 Aug 8 '15 at 20:05
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Ramps are usable when it makes sense for them to be. Try building some and see what happens instead of fretting over it - the game will tell you if they are unusable, after all. That said, I've tried to simplify:

  • There should be nothing directly above the ramp which would block a dwarf. You can't follow a ramp if it leads into the ceiling.
  • There should be a space next to the ramp which the dwarf can enter after following the ramp. You can't follow a ramp if it doesn't lead anywhere.
  • "The game will tell you if they are unusable" My miners are stuck underground again and nothing says the ramps are unusable. If it helps I made them through channeling. – readyready15728 Aug 7 '15 at 18:39
  • @Sadiq Did they channel multiple levels directly down? Ramps only go up one level. – Brilliand Aug 7 '15 at 19:18
  • They didn't. What I was doing was sinking a small tunnel west into the hillside where there wasn't much room for expansion. I then dug a 3x3 channel at the end of this tunnel to the next z-level. I then dug a tunnel east here to do further exploring. What this resulted in was a situation where all of the cells adjacent to the slopes either were open on the z-level above but had no wall on the z-level of the slope OR had a wall at the z-level of the slope but were not open on the z-level above. – readyready15728 Aug 7 '15 at 19:33
  • One of the several things that was not at all clear about the documentation is the logic involved here that I think is going on: that the two criteria in question have to be met simultaneously by the adjacent cell that is to be accessible from the ramp. That's how it should be written, like the actual algorithm involved. Also, the diagram provided on the Wiki has some Necker cube-like visual ambiguities and needs to be either changed or labeled or something. – readyready15728 Aug 7 '15 at 19:38
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    In any case, I have now realized that my trade depot can just be put on the first level and I can use stairs for the rest. Much easier than screwing around with ramps. – readyready15728 Aug 7 '15 at 19:43
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A ramp must be against a wall (corners are ok) and it must have an empty space directly above it. That's about it!

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