Organization (and Failures of) an Adventuring Party based military

[jseah]

I'm building this world for a story I'm writing and while the magic system doesn't really lend itself to the whole Hero-ing business, I would like to write about a country that doesn't really have a professional military.

Since this is pseudo-medieval fantasy already, I may as well do what I want. The military behaves much like a very large adventurer's guild, posting people places to solve problems and having a quest board for smaller stuff. While large groups of 'adventurer-soldiers' do exist to fight off the army-level threats, I'm kinda stuck on how they're going to be organized.
It can be assumed that the adventurers police themselves and it is generally unprofitable to turn to crime (there are a lot of adventurer-soldiers and even most villages do have a bunch of older ones that aren't so active anymore).

Obviously this sort of army has it's failure modes (probably a lot) and I'm trying to think of some as well.
Eg. the 'leading' adventurers tend to be off adventuring and killing enemies, so sitting around a fort defending it might be considered to be "easy work" and "not interesting". Also "not profitable". So even key positions that must be defended might be hard to get quality soldiers to stick around.
Eg. it's also quite impossible to keep secrets in such a military... maybe

What sort of benefits would it have? Better information transfer (if the adventurers share info)? Being very good at independent operations / asymmetrical warfare?

Any particular suggestions on these lines?

[VoxRationis]

Worse information transfer. Adventuring parties are likely to try to mislead each other or at least not help each other, out of the competitive spirit.

Less accountability in most cases—but less institutionalized protection of the adventurers, so abuse may or may not be worse than with regular soldiers.

Greater flexibility—assuming postings are reasonably accurate, adventurers with applicable skills will go where they are needed.

Limited control—Incentivizing, rather than ordering, means that you may find it difficult to distribute forces exactly as you need them.

Poor morale—Adventurers are essentially mercenaries, which are notorious for breaking when the fighting's gone against them. And unlike a regular army, good luck trying sacrifice ploys—that's Step 1 of plotlines that lead to the PCs killing their employer.

Plausible deniability—no, those weren't our adventurers, that was just a random group consisting of a rogue, mage, cleric, and fighter, that happened to rob your national treasury.

Limited operational endurance—adventurers don't really stick around very long, so occupation of territory will be difficult.

[Corneel]

For a bit of stability, you could add a militia system that would take care of keeping order and minor guard duties.

E.g. in towns all members of professional guilds are required as part of requirements of promotion from apprentice to journeyman to follow a short training and then serve one or two years as (part-time) guards and watchmen. At the same time, even after service, they could be required to do stints of training/exercising every few years and form a reserve in case of war (but not available for monster or bandit hunting, they have day jobs and minimal training after all). Officers and trainers would be hired by towns and cities from the adventurer's guild.

[Aergoth]

You might consider looking at historical cases where militaries have been supplemented by mercenaries.

Any venture of fortune tends to operate on the same principles, this one has a little bit of bureaucracy added to it (the guild itself) so let me posit a quick organization system.

Your Guild serves as the primary source of employment for all of these soldiers and so on. Presumably they provide training, lodging, equipment and various and sundry other services from wherever they're based. Your best bet then for modeling the guild itself probably lends itself to orders of knights. The Knights Templar for instance constructed fortified strongholds and provided financial services. The Knights Hospitallier (see also the Soverign Military Order of Malta) did much the same while providing medical care.
So where you have independant wealth, they might try to get in good with the Guild by offering funding to encourage certain guild activities in an area, providing land or what have you to the Guild for their operations to be based out of is a great way to ensure that there's a guild presence in your area.

The organization of the guild is probably hierarchial, where there is a single body or individual who runs the guild as a whole, and responsibility for various subdivisions trickles down in a sensible fashion. The Guildmaster(s) have various regional authorities under them, the heads of the various Guild-forts/Chapterhouses report to them and the individual captains of adventuring parties are at the bottom, organizationally speaking.

So, your adventurers organize themselves into groups based on the need to supplement their skills. The various jobs they perform include a monetary reward, the Guild likely taxes them for the privellege of taking jobs.

This is where the pirate/mercenary bit comes in. As a venture of fortune, meaning that no one is getting anything until the job is successful, you're depending on loot from the job to put money in your pocket. Spoils are going to be divided up as shares of the loot, either before or after taxes, based on the value of individual items. So someone could take the +1 Sword as their share, or they could take an equal amount of random objects of value (art, gems etc) so long as it doesn't exceed the value of their share. How a party divides their loot (evenly, unevenly, based on need) is up to them.

If you have a single higher-level adventurer leading a number of lower-level adventurers, this may mean that the leader takes more shares of the loot (effectively counting as two people or more) than the rest.

Alternatively, the entirety of the loot goes to some part of the party, and a salary is paid out to the individual members of the adventuring group. This is probably where the guys who deal with threats that require an actual military stand, receiving a general stipend for standing service and working in trades the rest of the time. Your adventurer-soldiers are basically a very well-organized, professionally trained and equiped militia provided by the Guild. They're sort of like reservists in that sense.

Here's where the problem is going to be. Your adventuring parties will be competing for the same jobs which will lead to situations like the head of vecna, the race through the dungeon for the same loot and assorted backstabbing. Also, the composition of the majority of a guild's forces is going to be uneven. Consider the actual adventuring parties as disparate groups of mercenaries if they have to work with the soldier-types mentioned above. They're better equipped and more skilled, but they're also separate groups and you can't mash them together into a single cohesive unit and expect it to work well.

[Avaris]

My approach would be that rather than a guild, with the guildmaster being the strongest adventurer and working their way up, have the 'military' follow a celebrity culture. Adventurers are promoted and build reputations based on their deeds, so there's a network of bards and promoters to support them. Famous adventurers are sought out to be a 'fighter in residence' and protect a settlement, and are paid handsomely to do so!