On walking through an underwater hallway and hearing speech or battle

[cmastah]

If PCs are forced to walk through a submerged hallway, how would I handle that? I doubt swim checks would be necessary since they're walking on hard ground, but they'd obviously move slower, how would I handle this in terms of checks?

Supposing the PCs are sitting in an area, do they have to actively roll to hear talking? What's the DC to hear talking? What about whispers? Battle also has me wondering, is it something you roll for (I THINK I know how to calculate the DC)? The problem is I see very few base DCs to be modified.

[Nephril]

call it difficult terrain. no check required.

a passive perception check of 10+perception could be assumed as a continual thing to see if the party notices stuff to speed up the game.

as for perception dcs read some modules or scenarios there are tons of references in there.

[cmastah]

Thanks for the tip, I think difficult terrain probably describes it quite well. I may end up simply telling them to roll perception to hear activity.

[Ravingdork]

Underwater Combat:

Land-based creatures can have considerable difficulty when fighting in water. Water affects a creature's attack rolls, damage, and movement. In some cases a creature's opponents might get a bonus on attacks. The effects are summarized on Table: Combat Adjustments Underwater. They apply whenever a character is swimming, walking in chest-deep water, or walking along the bottom of a body of water.

Looking at the underwater combat rules, linked to here for your convenience, the table says if you have firm footing, you move at half your speed, take a -2 to attacks, and deal half your normal weapon damage.

Please note that it is NOT difficult terrain, but a movement penalty. Among other things, that means it stacks. Someone walking along the bottom of a riverbed, making their way through thick kelp beds, for example, would only move 1 square for every 4 they expended.

EDIT: After studying "hearing in water" on the internet for about ten minutes, I would probably rule being underwater as "terrible conditions" and thus institute a -5 penalty for any creature not native to the terrain.

[Midnight_Angel]

I'd love to throw an additional comment into the mix.

Since the characters' bodies have a density that is quite similar to water, they should have something to weigh themselves down. Otherwise, firm footing is going to be an issue.

[King of Vrock]

The weight aspect is covered in footnote #4 of the chart in the section Ravingdork linked to.

[cmastah]

Thanks for the info guys (and you especially ravingdork, your posts have always been extremely informative :))