I ran through a prismatic sphere!

[Wonko the Sane]

That's just not possible per the spell description. It doesn't make a pit or anything resembling a pit. It can only be cast in walls. Even should you ignore the point about walls and allow it straight down in a floor then it still doesn't create a sideways passage underneath a wall.

I guess I thought it was a perfectly good (and creative) use of a spell, and saw no reason why a spell would be able to (or even care to) differentiate between a wall and a floor, both made of a substance that it can "make a passage through". Either way, the exact amount of matter rendered "not there" by the spell is the same. I've also allowed passwall to scuttle boats, even thought the resulting "passage" could hardly be used as such, and the hull of a boat is not properly considered "a wall". It seems to me that both uses seem to fall well within the spells purview.

If the wall’s thickness is more than the depth of the passage created, then a single passwall simply makes a niche or short tunnel.

What is a pit if not a niche in the ground?

As for the PC wizard not making his Spellcraft roll, he rolled a 1 vs DC 28 (his bonus was +26). Close, but no seegar. RAW, I shouldn't have even allowed a check:

DC 15+spell level.....Identify a spell being cast. (You must see or hear the spell’s verbal or somatic components.) No action required. No retry.

 

[Infiniti2000]

...and saw no reason why a spell would be able to (or even care to) differentiate between a wall and a floor...

I'm gonna focus on this comment, because I think it is a serious mistake. First, let me assure you that fun in the game is key, and I'm not here to tell you how to play. I'm just offering (attempting anyway) constructive criticism as I see it, so take it or leave it.

The above is a mistake IMO because you're modifying a significant concept of the spell. It isn't just the flavor you're changing (you should change the name from passwall to passsurface or something), but you're altering an important aspect of the spell for no real reason. The above (quoted) justification is completely insufficient and especially dangerous as a guideline. It leads to a slippery slope of which you cannot recover. For example, "I saw no reason why a spell would be able to (or even care to) differentiate between an ally and an enemy." I'm sure you can see how truly an enormous impact that such statements would begin to have on your game.

One other comment on creativeness. Allowing creativity for spellcasters is all fine and great, but don't leave out the non-spellcasters. Give them some equal-power outlet for creativity or you need to not let creativity for spellcasters not get overboard (and in this case maybe you haven't).

What is a pit if not a niche in the ground?

Okay, it is, but your comment is a non sequitur. To show why, answer this: what is the thickness of the wall of the ground? Makes no sense, right? Thus, you can't start using the word 'ground' where it doesn't belong. Or, if you want to remove words from the description, I get to remove some, too.

RAW, I shouldn't have even allowed a check

Sure you should've. As you said previously, he heard the spell.

 

[moritheil]

RAW, I shouldn't have even allowed a check:

Listen check followed by Spellcraft.