Underground Travel

[Primitive Screwhead]

Sounds like more of a plot-driven timeline than anything else...

One potential is to offer 'cautious travel', half-speed and the Rogue gets to the equivilent of a Take 10, with a +2 or +4 courtesy of Aid Another actions... this allows for the group to search for traps while still moving relatively quickly.

Or if they are in a hurry, a Take 0 with the +2 for Aid Another while moving full speed. I tend to use these rules to speed play whenever I have a paranoid Rogue in the group.

Sounds like an interesting adventure, you do need to have a couple of vermin swarms in there if refuse is simply piled off to the side

 

[taliesin15]

Plot-driven to a large extent, yes. I'm trying to have something where there's enough time for the party to take whatever route they want, but not get bogged down stirring up a hornet's nest, with, uh, say, the tribe of beholder mind flayer liches...as to having swarms in the rock-filled in chasms that's kind of interesting. There's definitely a lot of life down there, including things like edible fungus/lichens, which are eaten by insects and animals at the lower end of the food chain including these white pigs, which are the main fodder for the humanoid races in this underground region.

 

[Ogrork the Mighty]

In general, underground travel is far slower than overland travel. That being said, if it's a relatively high traffic area, there's probably the equivalent of trails (or possibly even roads) that could speed up what would otherwise be agonizingly slow travel. Those "easy" routes, however, would of course be more dangerous as travelers would naturally gravitate towards them.

For unmodified speed, I'd look at the biggest negative modifier and use that for underground travel. Off the top of my head, somewhere around 1/6 speed over the course of a day might be a good place to start.

I wouldn't say that adventurers need to be actively searching every 10-foot space they travel through. That's just slowing the game down unnecessarily. It's also very unrealistic to expect that level of scrutiny over prolonged periods of time and distance (imagine patrols in Vietnam actively searching every 10-foot space they move through, rather than scanning ahead for traps). Just halve whatever speed they're traveling at and let them make a check (possibly a Spot check for anything out of the ordinary, with success allowing for a Search check to find the trap) for any traps they encounter. Make it clear that they can be super cautious, but it will dramatically slow them down and potentially expose them to even greater dangers in the form of random encounters.

 

[Kmart Kommando]

Taking 10 does not take any more time than rolling the skill check.

Though most CR appropriate traps make taking 10 useless 95% of the time.

1/2 speed for search and move, 1/2 again for difficult terrain if it's natural caverns, assuming all PCs can make the basic climb checks by taking 10. So basically 1/4 speed 'overland' movement.