Mercenaries can be used in a wide variety of roles. In fact, they are already an integral part of most fantasy RPGs, though they are rarely defined as such.

Most hirelings of the PCs will be lone mercenaries of one sort or another. The warriors, wizards, torch bearers and so on who hire onto a party for a share of the take are sell swords; the troops a PC hires to help defend his new land holdings are mercenaries also, as are the strange, assorted warrior types who hang out at seedier bars, looking for work of one sort or another.

The people the PCs hire shouldn't be treated as faceless monster fodder, either by the GM or the players. The GM should create some kind of brief background for the merc characters, and keep in mind that he will have hired on purely for money. Many mercs. especially the more experienced ones, will haggle for their terms. will the merc get an equal share of the profits or will he receive a regular weekly/monthly pay? will he be expected to provide his own equipment and transportation? will he be given a proper burial if killed?

If the terms of the contract worked out between the PCs and the MCTc are at any time rendered null (if the PCs leave him to die at the hands of a murderous dragon, for example) the merc should be allowed to withdraw from their service without fear of reprisals by his employers.

Like most professionals, mercenaries have a great deal respect for one another, and whenever they get together, they'll talk. If the PCs get a reputation as shameless exploiters, they will soon find they cannot hire anybody or worse, the mercs they do hire will work to make sure the party fails as revenge for their comrades ("Gee, Mr. Starkiller, I have no idea how my torch went out just as that Dark Overlord of Slithering Doom attacked you guys. Say didn't you used to have two eyeballs?")

Keep in mind, though, that not all mercenaries are honorable, and some will skip out on contracts whenever convenient or profitable. This can cause all sorts of mayhem for a party who may not be expecting it (What do you mean Stylik and all the horses are gone?)

Mercenaries can also be used as casual encounters, allies, contacts or opponents in a campaign.

PC mercenaries

Most player character parties are by definition mercenaries, hiring out their talents as a fighting force to whoever can pay enough. however, instead of just taking odd jobs that seem to blow their way, some groups may incorporate and actively seek employment in nearby armies, in effect becoming the type of small mercenary band as described earlier.

The nature of their employment will depend greatly on the character of the party. If the PCs are made tip mostly of one type of character (magic wielders, for example), then the group as a whole will be hired in that capacity, the other PCs treated as assistants or dependents of the primary hirelings.

If the PCs are a well mixed lot, they Will usually be assigned either as foot soldiers or a specialist team assigned to one of the army's lower commanders as part of a company or battalion.

Typical adventures for mercenary parties include participation in battles, foraging, raiding, scouting, spying, being caught behind enemy lines, special missions, couriers, and hanging out with army regulars (not all the regular soldiers will be unfriendly.) If given command of actual troops, they may he ordered to capture and hold territories and towns. quell rebellions and insurrections, deal with insubordination and mutiny, and endure the derision of the officers above them.

The PCs may also hire themselves out to a large merc company. This is probably the best option for the group, as they will be treated as equals within the company, have good deal more freedom than working for the army directly, and still have to answer to an authority figure for the convenience of the GM. merc companies tend to have far more colorful characters than army regulars, lending themselves to better role playing opportunities. Adventures will pretty much be as described above, but now within the context of the larger company.

Conclusion

Mercenaries can add a great deal of depth to armed conflicts in your campaign if handled properly. They should always be portrayed as something much more than faceless sell swords; they uphold a tradition as ancient as warfare itself.

Sell Sword Blues: Mercenaries in Fantasy Campaigns