Adventures for militia/soldiers/tribal warriors

[Yora]

I am working on a setting for a campaign that is all about the PCs being part of the defense of their community. In this particular case it's warriors of a barbarian clan, but I think having PCs as militia members or soldiers is mostly a difference in fluff, but not so much in substance. The real difference to a regular adventuring party is, that such characters wouldn't be motivated by finding treasures or simply out of the goodness of their hearts. Not being mercenaries but having responsibilities towards a specific settlement or realm does change to some degree what kinds of adventures the PCs would go on, or which would seem a bit inappropriate. On the other hand, being tied to a specific place and people, there are far less options to refuse or avoid certain dangers, because it's the PCs job to deal with them and they wouldn't really have anywhere to return to if they would turn their backs on it.

I just want to collect some basic ideas for adventures that would work well for such parties when planning a campaign.
So far, I've come up with seven types of goals, that should make for good and appropriate adventures.

Destroy a threat to the settlement/realm: This thread could be a monster that has made its lair to close to the town, bandits that raid outlying farms or attack travelers on the road, a new outpost of warriors from a hostile neighbor, or even a small invading army that is already attacking the realm. The objective of the PCs is to locate this thread and put an end to it, one way or another. Relatively easy and straightforward. Locate the danger and either destroy the enemies or make sure they don't pose any threat in the future.
Take control of a new outpost: Basically the same thing in reverse. The PCs are tasked with establishing a new secured base for their own people at the edge of their realm. That means clearing out any previous inhabitants and fortifying the place to repell any attempts to drive them out.
Find or retrieve an object: For whatever reasons, the PCs have to find an object of a certain kind and bring it back to their town. That could be magical ingredients, plants or animal parts for medicine, stolen jewels or relics, secret documents, and so on. The goal is primarily that the object is returned to the PCs town, regardless of how they accomplish that. In many cases, opponents might be persuaded to trade the object for something without violent confrontations being neccessary.
Capture or kill an enemy: Could be an enemy leader, a criminal, an assassin, or an escaped prisoner or spy.
Rescure an ally: The person or people could be captured by enemies, or simply lost or trapped. While similar to hunting an enemy or retrieving an object, the stakes would be quite different, changing the tone of the adventure and also the kinds of risks the PCs might be willing to take. A botched assassination can be tried again, but a rescue attempt might not. Also, whatever the PCs do to attack enemies must not harm the people they want to save.
Escape from danger: The PCs are trapped in some way or another. Be it being captured and in prison, trapped in a cave, or just having the path to their main goal blocked by dangerous monsters. The only objective is to stay alive and get out of the place.
Explore or scout a location: It could be that a formerly unknown ruin has been discovered or that the superiors of the PCs require new information on the current situation in a specific location. This might potentially lead to situations where the PCs will also attempt to destroy a threat to their town or retrieve an item valuable to the town, but the setup merely requires them to explore and return with information. Destroying monsters or retrieving treasures could be done in a follow-up adventure as well.

Does anyone have more idea for adventures that characters would take for reasons other than payment and riches?

[BWR]

Are you asking for motivation or ideas? Because 'the boss tells you to do X' should be all the motivation you need to run just about all of traditional adventures. And as for advetnure ideas...just about all traditional adventures. Just rework them a bit so the good of the community is in some way affected by the situation and outcome of the adventure.

[Berenger]

Escort a convoy / VIP Escort your princess to her marriage with a local warlord to establish peace between your principalities. Bodyguard senator V. Arus, the new magistrate, during a court hearing involving various squabbling tribes. Distribute those carts full of grain and supplies among your forts before winter.

Hearts & Minds Mission Curry favor with the locals by... dunno. Giving bubblegum?

Establish infrastructure Build a road / aqueduct / bathhouse / school. Organize logistics, motivate your men and the locals, look out for sabotage. Watch your standard of living rise.

[Yora]

Escort is a really good idea I'd never been thinking of before. I think I've never seen any such adventures in published modules, probably because they lack a big villain that would be defeated in a final battle. But as part of a longer campaign, this could get really interesting. Avoiding fights and making a run for it would be much more attractive coices than they usually are.
It could easily be used as a direct follow-up to a prisoner rescue. I really like that one.

[SethoMarkus]

Internal Review: Corruption is spreading within the higher-ups of the community; you've been trusted with seeking out the traitor and quieting any resistance.

(Threat of) Civil War: For some reason the town/city/state has been split. Do the players stay loyal to the established order, or do they fight for the defecting faction?

Guard Duty: Kind of expected, but basic guard duty. Maybe a faire is in town and the large crowds need special attention, or maybe the city has a busy market to begin with. Plenty of standard "thief in the crowd" adventure hooks here.

Foreign War: Kind of already covered by OP, but players are sent as reinforcements to help a national ally in a war. Their loyalties aren't tied to the fight, so do they engage in heroics or just do what needs to be done to get the job done and go home safe? If they desert, their families and homeland would most likely remain safe (for some time), but what will happen to the foreign allies?

[BayardSPSR]

Peacetime: Soldiers can get up to some wacky hijinks when they're off duty. What they do off-duty could be just as interesting as what they do on-duty (it's very much the case in real life).

As warriors of a barbarian clan, they may have other peacetime occupations, if they're more of a militia. If they're more professional huscarl, sworn-to-a-lord types, they might have more downtime.

Edit: Think of the Three Musketeers! Technically professional soldiers - but most of what they spent their time doing was completely unprofessional (or had to do with internal intrigue, at best.

[Eric Tolle]

Hosting a parley: two tribes/clans/villages/whatever have been feuding and fighting for ages over land, cattle theft, or other old grievances. Now your village is hosting a meeting off the two sides. If all goes well, your village will gain a great deal of honor as peacemakers. But some of the younger clan members on either side will see this as a chance to gain honor by starting a fight. And maybe some people in the your village stand to gain from the feud continuing...

Cattle gone: the occasional cattle raid is an accepted part of life. But now a clan's entire herd has gone missing without a trace. The clan heads naturally blame a rival clan. Can you find out what happened before the clans start fighting?

The ruins: Smart villagers know the best way to deal with the ancient ruins on top of the hill is to avoid them. But some children have no sense; now the little girl is looming and acting strangely, and ominous lights and music are coming from the ruins. Can anything be done to fix things, or is the girl, and maybe the village doomed?

The ghost: the spirit of a recently deceased young woman has appeared. As vengeful spirits go she's not too bad- she's easily appeased by beer (for now), and is as cute as she was in real life.Still she IS the restless dead, and something should be done. She says she'll rest if her murderer is brought to justice, which is a problem because nobody knew she HAD been murdered. And ghostly memories being spotty, she's not sure herself who killed her...

The Witch Hunter: after a series of unusual accidents, some fool called in a witch hunter. As he "investigates", simmering tensions and resentments come to the surface, and accusations and counter-accusations start flying. Can the watch get to the bottom of this before things get out of control? A complication might be a local witch, who has to be kept out of sight of the witch hunter, and also appeased lest SHE start something.

Adventure Time! The most dangerous thing that can happen to a village has happened: a group of adventurers finished stirring **** up in the mountains, and has descended on your village to recuperate. From spending too much gold, to chasing attractive young people (married or not), to passing off dangerous bits of magic, these are powerful, violent people who need to be handled carefully. Play up the eccentricities and annoying elements of adventurers. Naturally children will be fascinated by these fools, and perhaps will want to follow along on their adventures, to the distress of their families. And maybe you've been living relatively peacefully with the goblins and trolls of the mountains, until some violent idiots attacked them and took their treasure...