I'm out of ideas

[jontherev]

3 words: Legion of Doom!

 

[Jondor_Battlehammer]

Have them encounter a goblin with levels in psionics.

 

[Thurbane]

Two warring factions are fighting for power and influence in the swamp:

~ A tribe of Lizardfolk barbarians, led by a Half-black-dragon leader...

~ A group of Trolls, led by a Greenhag sorceress...

 

[kolikeos]

Hmm,

grab a lot of interessting swampy monsters for "random" encounters, let them find a clue (like the rotten cadaver of a human who might have worked for the wizards)

They might use magic to find something out about this cadaver or they might not.

If they do, use the cadaver to point them closer to the wizards base, if not, wait and see what they do, try to give them other clues.

The wizards might have enslaved several of the evil humanoid tribes. They might even send in their troops to gather "raw material" for their experiments.

I think this is a good scenario to play "sandbox style" ... instead of thinking about what will happen next, decide what happens in the swamp, connect most of it in some way to the wizards or their base (There might be a black dragon in the swamp who happens to know where the base is, because his lair is next to it. The wizards first tried to control him, and then drove him away after that failed. He will start an encounter with a "You are working for them? Now die!" ...)
etc.

“Sandbox style” might just be the thing I need here. Why did I not think of that?

Huge swamp. No civilization. I'm thinking a black dragon. Or a green one. Or both. Maybe they're at war, and using humanoids as proxies. The players inadvertently stumble into it. But our dragons are smart, see? They know the PC's are more powerful than ten-times their number in humanoid yard-trash. So they both attempt to "persuade" the PC's to aid their cause against their mortal enemy (with a carrot and stick approach, "I'll perhaps give you treasure and perhaps not eat you."), with the desired end result of both ruling the entire swamp and eating the party.

The green dragon/black dragon war sounds like great fun. One might be on good terms with the wizards and the other hates them. Of course, even the one who hates them won't help the PCs for free, and the other one may be persuaded to betray the wizards if the offer is good enough.

I'm thinking war between humanoids from different villages. One of the villages approaches the PCs for help with raiding the other village. In return, they could share some information about the whereabouts of the wizards...or their humanoid employers could even betray them to the wizards (ideally right after raiding the other village so that the party's resources are somewhat depleted).

Chad

Yes, I was thinking of something along those lines also. Each of the tibes can tells the PCs something they need if the PCs help them against one of the other tribes, and they might also find some clue in each of the villeges they raid.

With 9th-11th level characters, odds are good the entire swamp will be bypassed in a matter of hours.

Find the Path, Commune, Commune with Nature, some Overland Flight or Teleport to get there. If you're fortunate, the PCs will actually interact with the denizens of the swamp to extract information through diplomacy, intimidate, detect thoughts, charm person, dominate person, or speak with dead, if necessary.

If they don't have to, or don't see any profit ( or good deeds to be done, if they are that type ), then they are likely to skip over as much as possible.

The only divination magic they have is scry. The only trasportation (apart from walking) is a small flying carpet (can 5 characters actually fit on a 5 by 5 carpet?). And they have rope trick for camping.

 

[Whisper72]

Well, if the swamp is that large (half a continent), odds are there are large parts of relatively deeper water. This means that there will be a lot of boating going on. Think Pirates!! Maybe there are entire floating cities! The city base of the wizards themselves may also be floating, and therefore not in one fixed location, and thus difficult to find. This immediatley makes teleporting there kinda difficult as well... Agents of the wizards need to be able to find the place though, so higher up agents may possess some kind of homing device which the PC's could find and have to figure out how it works.

Definately go with the lost civilization theme and the wizards mining the ruins for powerful magic. Subplots may revolve around the PC's in a race against time to gather several items before the agents of the wizards get to them, thus forcing the wizards (or at least their agents) to come to them...

 

[Phlebas]

Lizardfolk druids.....

plus all the good ideas above, but i just like lizardfolk druid for that unblinking "So why should i care about your petty little intrigues" look at the PC's just before threatening to leave them alone in the swamp....

 

[Baron Opal]

Zombie wasps.

And I don't mean insectoid undead. Used them to great, creepy effect when my PCs were blasting their way through a jungle.

 

[roguerouge]

Use the terrain and the ecosystem. Make your skill monkeys shine. Sinkholes, infections, swarms of leeches, swarms of mosquitos, things attacking while you're dealing with swarms, oppressive heat and humidity, cover and concealment for every combat, difficulty in finding dry places to sleep (although rope trick may make that more difficult), higher survival checks to find food (do not hand wave that one) due to unfamiliar and hostile terrain, things that track them, and animals that find any mounts they bring in... tasty, because I challenge you to use rope trick on a horse.

 

[Halivar]

Wait! Scrap the dragons! Scrap the humanoids! Scrap the campaign!

A whole continent of swamp? I got one word for you, my friend: R'lyeh.

Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn!

Just kidding. I think you should do the dragon-war thing. With chuul-riding lizardmen.

 

[Stormborn]

Wait! Scrap the dragons! Scrap the humanoids! Scrap the campaign!

A whole continent of swamp? I got one word for you, my friend: R'lyeh.

Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn!

Just kidding. I think you should do the dragon-war thing. With chuul-riding lizardmen.

Hmm...OK I know this doesnt technically work by the RAW but how about:
Abysal paraillithid half-green dragon giant psion?