How to effectively use *Pit* spells

[Gauss]

Dr. Grecko, why would you only use the opposing walls when you have side walls to help? 4walls (chimney) is easier to climb than 2walls (canyon or hallway). I feel the rules represent that.

- Gauss

[garvdart]

ready action pit...1rnd/level.....next spell...
...black tentacles...duration 1rnd /level.covering the entire pit+walls...

in a corridor or cave....ready action pit...rock to mud the ceiling...next round dismiss the spell...there now hip deep in solid rock and have taken 3d6 fall, 8d6 from the cave in....

[zefig]

I've been figuring I'd create pits then cast wall of stone over top of them. There doesn't seem to be any sort of real rule on that interaction though.