ToME WikiHow is 'find secret passages' supposed to work??????
There's no documentation. The first time I tried it, I was supposed to select a random square, so I selected a wall square. "There is no wall there." was the approximate response. No I'm not even prompted for a square to select. I just get the same response. What's going on?
NeilStevens: It works like the spell Probability Travel, I think.
HarryErwin: That would require you to choose a direction instead of a square. <Tries to think, but nothing happens....> OK, I deliberately bumped into a wall to reset whatever was having a problem... Now triggering the ability and trying to walk takes me to the next open space. The user documentation could be improved...
Say, I wonder what happens if I hit the up or down key....
GreyCat: There are definitely bugs in the find secret passage power. For example, BugReport202, BugReport295, BugReport296. We might as well add "user interface is not intuitive" to that list. 
As far as I can tell, how it's supposed to work is: you stand next to a rock wall, and activate the power, and press the direction key as if you were going to walk into the wall. Then you pop out on the other side of it. And that certainly works, in my experience... but see above.
HarryErwin: Except that sometimes you keep going unexpectedly. I suppose it's because the space contains a monster, but I scanned beforehand, and it looked empty.
Grant: It actually works exactly like a one-shot probability travel, except it is innitiated differently, which allows you to start it while by terrain you can move over and monsters you can attack. Like probability travel, it allows you to move to the next open space in the direction you designate, subject to the following restrictions: It will always take you outside of a vault (or other special room like the princess quest) if it moves you more than one space. It will skip open spaces in vaults if you are outside one, unless the vault abutts a wall in the direction you are traveling, in which case it will dump you out before the vault. Spaces with monsters do not count as open spaces (so you can use it to move to the edge of a horde that's been summoned around you). Spaces with lava do not count as open spaces in the middle of a jump. All colored wall squares except chasms do not count as open spaces, whether or not you can transverse those squares. With chasms, if you try to innitiate by one if you can't cross them, you will get a "you can't cross the chasm" message. If there are no open spaces before the edge of the map, it will create one at the edge of the map to dump you in. On special levels you always get a "that's not a wall" error message and it does not trigger. So there you are, it's not buggy, it's just got a lot of rules. (I use it or probibility travel with all my characters. With grow trees/thauma wall creation + anchor of spacetime it makes you nearly invulnerable).
VeryFoobar: It also doesn't trigger traps you land on. By the way, can you use it if you have Yavanna roots active?
EwanMcNay: This month's DitL character - which is where all the interest is coming from! - has really converted me to this special power as an escape hatch. Tha ability to both target direction and go through monsters is great, and I actually found it quite intuitive. The one time it wasn't was when running Manwe temple quests with their mist-lined walls, which I would try to find a passage through only to move just the one step. I suspect that I may try this on Mt. Doom for ring disposal, almost as good as Flare (and better sometimes, if there are no convenient swappable monsters).