Tips on a combatless session?

[Titanium Fox]

Hiya everyone.
Right now, I'm running a 3.5 campaign in the 'sandbox' format. Basically the way it works is that I have 19 players, and each Thursday 6 - 8 of them show up, and go off on a quest/mission. The backstory is that they are soldiers of the military academy of Crystalden, and each session they receive an order from their higher ups to go out and make some effort towards the war against the Yuan-Ti cultists of Erythnul that has been raging for the better part of a century.

Anyways, now that the party has hit an average of fifth level, I'd like to start branching out based on who shows up. If my Crusader and Fighters show up primarily, I want to send my party on a dungeon crawl. If it's a healthy mix, some sort of tracking mission to a single large boss-mob.

However, what can I do to challenge my players without using combat at all for the entire session? The only thing I can think of is something like gather information to obtain a powerful item or something, but honestly that's it. So yeah, any and all suggestions are definitely appreciated. Thanks everyone!

[Grogmir]

Kidnap!

Some dastardly agent of evil has kidnapped someone of importance or young and good.

Get going track him down!

Stage 1 - Gather information.
Streetwise, Diplomacy maybe a little perception

Stage 2 - tracking down
Athletics, Endurance, Perception, Insight

Stage 3 - Interogation (He's hidden the hostage!)
Intimidate, Diplomacy, Bluff

Stage 4 - A RACE AGAINST TIME. (Get a sand timer - turn it - really freaks your players out!)
Athletics, Acrobatic, Endurance

Stage 5 - Disarm the trap (classic drop in an vat of Acid?)
Thievery, Religion, Arcana, Endurance, Athletics,

[valadil]

My best non combat sessions have been the social ones. Not party face vs NPC social, but PCs talking amongst themselves, in character. For this to work, you need your PCs to have opinions about things and you need to give them a problem without a clear cut solution.

The easiest way to do this is with planning. Give them a task that isn't solved by any one spell or ability they have. This is easiest at low levels. For instance, when I started running my thieves guild game, the quest to get the players into the guild was that they had to steal a keg of beer from a bar, while it was open. They spent two hours figuring out how the heist would go down. They talked about some hypotheticals and then scouted out the available bars and picked one. I think they ended up distracting the owner and swapping a keg for a barrel full of sea water.

The other way to get PCs talking is to give them something to speculate about. A mystery works well here. You don't want to make it an obvious mystery though. What I mean by that is that if you play it out like a skill challenge there will be nothing to talk about. They'll roll search checks at the scene of the crime, gather info on the nearest witness, and intimidate on the suspect's friend. You need a situation where they don't know the next move and so they have to figure it out for themselves.

Anyway, for your game I suggest a corrupt superior officer. Maybe have someone taking bribes or acting as a spy. The players would notice something off in the person's behavior. (Don't tell them there's something off, just change how you act as the NPC). Maybe some loot or evidence went missing. Maybe the bad guys knew exactly where the PCs would be. Your players might figure out someone above them is screwing with them, but it will be up to them to figure out how to narrow down the possibilities. And once they've done that, they'll have to figure out how to confront the problem.

[Notreallyhere77]

Kidnap!

Some dastardly agent of evil has kidnapped someone of importance or young and good.

Get going track him down!

Stage 1 - Gather information.
Streetwise, Diplomacy maybe a little perception

Stage 2 - tracking down
Athletics, Endurance, Perception, Insight

Stage 3 - Interogation (He's hidden the hostage!)
Intimidate, Diplomacy, Bluff

Stage 4 - A RACE AGAINST TIME. (Get a sand timer - turn it - really freaks your players out!)
Athletics, Acrobatic, Endurance

Stage 5 - Disarm the trap (classic drop in an vat of Acid?)
Thievery, Religion, Arcana, Endurance, Athletics,

All good ideas, but this is 3.5; the skills are not skill challenges, and have different names. How could you make these engaging in the 3.5 skill format?

[valadil]

All good ideas, but this is 3.5; the skills are not skill challenges, and have different names. How could you make these engaging in the 3.5 skill format?

Skill challenges work just fine even if the system your using didn't write them. They're just a series of skill checks.

[Notreallyhere77]

Fair enough. I never got the hang of them, though.
Sorry to nitpick.