I made reference to this in the venturer questions thread, but I made an abstracted system for resolving the results of mercenary guild actions. This is my first-final draft (in the sense that it is not the first thing I scratched out, but is the first version I felt was complete and good enough to be worth sharing. Let’s call it a beta.)
You can see it with tables here: http://aryxymaraki.pbworks.com/w/page/94527227/Mercenary%20Guilds
The entire text is reproduced in this post, but no tables, so it might be harder to read. Feedback would be great! The expected income is, most of the time, lower than a hideout, but I think Sir Dragons-A-Lot (who somehow has all of his units be dragons or other very high BR units) might make more than generally expected.
A mercenary guild is intended as an alternate domain game for any class who is interested in it, but primarily for fighters and fighter-types. It is intended as a bridge for mid-level play to allow a lower-level domain game than true rulership, providing an introduction into the means and methods of conquest and rulership without requiring the same level of investment. Like domains, any character with sufficient money may found a mercenary guild. Those who have free followers from their class will be better at it, as this will provide them with mercenaries that they do not need to recruit.
To found a mercenary guild, a character must construct a guildhall. A guildhall may be constructed in any city or town (Market Class VI or better). The size of your guildhall is limited by the size of the city it is founded in.
Market Class - Maximum Monthly Wage - Minimum Guildhall Value
VI 800 2400
V 1600 4800
IV 3000 9000
III 12000 36000
II 25000 75000
I 100000 300000
The combined total wage of all mercenaries working in your guildhall may not exceed the maximum wage by market class. (Note that this means that in a Class VI market, your guildhall may only support a single unit of infantry, or two units of conscripts!) (A second note is made; if you prefer to phrase the maximum in terms of Battle Rating, remember that the monthly wage of a unit is equal to its Battle Rating times 720. Thus, to phrase the maximum in terms of BR, simply divide the maximum wage by 720.)
In addition, a minimum investment in your guildhall must be made in order for mercenaries to take your guild seriously. The minimum investment by market class can be seen in the table. This investment represents housing, connections, supplies, as well as ready cash on hand for paying of wages.
Once you have your guildhall built, you need to hire mercenaries. Hiring of mercenaries follows all rules as described in ACKS Core and Domains at War: Campaigns. However, in order to hire them as bonded members of your guild, you must pay them three times their normal monthly wage up front.
Once you have your mercenaries hired, you may then send them on operations. A unit may be assigned to one operation per month. Like hijinks, it requires the full month; the unit may not do anything else while it is assigned to an operation. (If you wish to garrison your domain with units that are part of your guild, and then also send them on operations, this will invoke all relevant penalties for having your garrison out of your domain.) This document describes four different types of operations; the Judge should feel free to design more.
A unit sent out on an operation must make a throw to judge its success, and a roll to determine how much cost was incurred. The default success throw target number is 18+. A bonus of twice the unit’s Battle Rating is added to this throw. (Thus, a unit with BR 1 will roll 1d20, adding 2, and succeed if the modified result is 18+. A roll of a natural 16+ will be a success.) A unit that succeeds realizes a profit determined by the operation. A unit that fails is paid nothing.
Independent from success, costs may be incurred. To determine the cost incurred, roll 1d20 and add twice the unit’s Battle Rating. The cost will be equal to the modified roll times 100 GP. (Thus, if you roll a 7 with a unit of Battle Rating 1, the cost will be 7 + 2 * 100 = 900 GP.)
A roll of a natural 20 on a success throw indicates a great success; see below for details on a great success. A roll of a natural 20, or modified 21+, on a cost roll indicates a catastrophe; see below for details. (The details on great successes and catastrophes can be found below the rules on operations.)
Note that income and success are an abstraction of all possible sources of income and cost, including wages. A unit that is assigned an operation does not need to be paid their monthly wages; that is included into the abstractions of income and cost. Income includes all sources of income; the actual amount they are paid by the client being only one source (loot and ransomed prisoners are other major sources). Similarly, paying their monthly wages is only one source of the cost; replacing lost men, paying for property damage caused, and so on are all potential sources of cost.
A unit assigned to patrol is given an area to patrol against threats. Patrol duty is almost always in civilized areas, and is thus the safest and easiest of all the operations described here. Consequently, of course, it pays the least on success. A unit on patrol duty adds 4 to their success throw and subtracts 4 from their cost roll. A unit that successfully patrols their area has an income of 1,800 GP.
A unit assigned to guard is given a specific landmark or area to guard against threats. Guard duty is almost always in borderlands areas, making it more dangerous than patrol duty but still not the most dangerous thing a mercenary unit can do. A unit on guard duty adds 2 to their success throw and subtracts 2 from their cost roll. A unit that successfully guards their area has an income of 3,000 GP.
A unit assigned to escort duty is given a moving target to guard. It might be a trade caravan, or it might be escorting a royal or other important personage or item to be delivered. Regardless, the task involves travel, often across borderlands or wilderness areas. A unit assigned to escort duty has no modifier to their success or cost rolls. A unit that successfully escorts their charge has an income of 5,000 GP.
A unit assigned to pitched battle is hired for a specific military campaign and will be expected to be in active combat one or more times on the operation. Pitched battles are the most dangerous type of operation, and of course, pay the most as a result. A unit assigned to a pitched battle subtracts four from their success throw, and adds four to their cost roll. However, if they do succeed, they have an income of 10,000 GP.
The four operations, summarized in a table, can be seen below for convenience.
Great Successes and Catastrophes
As mentioned above, a natural 20 on a success throw indicates a great success, while a natural 20 (or modified 21+) on a cost roll indicates a catastrophe. When one of these occurs, roll 2d6 and consult the appropriate table.
2: Lucky strike! The unit manages to lay its hands on an extra 1d6*100 GP. (The Judge or players are encouraged to describe what happened to give them this money.)
3-5: Clerics arrive to minister to the unit’s needs. While the clerics remain, subtract 1 from all cost rolls the unit makes. (Clerics will not stay with a unit that has camp followers.)
6-8: Good omens make the unit more confident; add 2 to their next success roll.
9-11: Legendary leader; until the unit’s commanding officer is killed, add 1 to all success rolls this unit makes.
12: The unit becomes a veteran! Adjust their battle rating and wages as appropriate. If this places your guildhall above its maximum wages, you do not lose any units, but you may not hire more.
2-: The unit is wiped out!
3;5: An officer is killed; apply a -2 penalty to the next success roll this unit makes due to green officer.
6-8: Disease strikes the unit; they must lay idle next month recovering.
9-11: Camp followers attach themselves to the unit. Until dealt with, add 1 to all cost rolls this unit makes. If the camp followers are driven away, apply a -2 penalty to the next success roll the unit makes.
12: Extra costs! Due to some bad luck, the operation costs an extra 1d6*100 GP. (The Judge or players are encouraged to describe what happened to increase the costs.)