Everything below is subject to change.
This is the first draft of the mercenary changes, which are designed to make it worthwhile to hire mercenaries, and to show the true difference between a professional army and the feudal armies, mostly constituted of levies taken from the peasantry, serving for the landed lords.
The ambusher upgrade has been changed (this should have been done long ago, I'm just making it official now).
Mercenaries now have access to unique upgrades, called Branches and sub-branches, which are only accessible to them. All these upgrades cost 1,5d. To upgrade mercenaries, one must first purchase a branch, which can then be upgraded into a sub-branch. These stack, count as only one upgrade, and have an upkeep of 1,5d. This effectively allows mercenaries to have an equivalent of four upgrades in total, while paying only the upkeep of three - thus making it easier for mercenary captains to make profits. However, hiring mercenaries is complicated; since captains have no manpower available directly, they must rely on guilds, which means recruiting a mercenary may at first cost more, or force the captain to go on a mission. Lords wishing to hire mercenaries can contact guilds and bands roaming the land, but they are costly and the other side can use them too.
Landed lords cannot hire mercenaries. If a mercenary captain receives land, he may found a mercenary guild, which can continue to hire mercenaries. He will not, however, receive any income from this land; it will be entirely used to pay his men's upkeep or, if there is surplus, go to waste somehow. Of course, a mercenary captain may also choose to become a lord, in which case he will be able to convert his troops into upgraded normal troops, with new upgrades of his choice (Heavy II and archer II count as two upgrades each; the third ranks are not available to convert in). This is more for balance than for IC reasons.
Mercenaries can be upgraded in one month, which means that they can be upgraded and used immediately after in any situation UNLESS THE GM SPECIFIES OTHERWISE (in the case of a siege or in the middle of a campaign, for example).
Note: Priests can hire Mercenaries, but only upgrade them in the Templar Branch. Mercenaries can use all three branches.
The following upgrade has been rewritten:
Ambusher: +1 to ambushing supply trains, allows roll to ambush enemy forces (on success, strength bonus of 20/40/60 %). An ambush must be performed from a hidden initial position - ie woods, hills, marshes... Common sense will determine if an army can ambush (and the GM's common sense is superior to the player's at all times)
Soldier branch: +1 strength / Tactician upgrade
Soldier sub-branch 1: Elite fighters: +2 strength / Can negate terrain bonuses (10% * Number of units with the upgrade, up to 100% [50% if assaulting a wall])
Soldier sub-branch 2: Siege engineers: Can build temporary siege engines for a reduced cost (-50% cost, lasts only the duration of a siege) and repair bridges for free in a logistics roll (d10 - any other bonus in logistics - number of siege engineers = number of weeks). The number of units with this upgrade is the maximum number of temporary siege engines that can be built.
Soldier sub-branch 3: Cavalry: Standard cavalry upgrade.
Ranger branch: Ambusher upgrade / Logistics bonus (applies only if all the units involved have this upgrade)
Ranger sub-branch 1: Skirmishers: Archer upgrade and +1 strength on the offensive
Ranger sub-branch 2: Wild warriors: Additional logistics bonus. Weather and terrain have no effect on logistics.
Ranger sub-branch 3: Night warriors: Can attempt an ambush during the night even without an hiding point, and said ambush can be attempted on the offensive (attacking a camp in the middle of the night, for example) with a -1.
Templar branch: +2 strength. +4 strength when fighting Heathens.
Templar sub-branch 1: Holy Warriors: +2 strength when fighting under the orders of a priest of some sorts.
Templar sub-branch 2: Swords of Gods: Receive a 50% strength bonus when fighting a stronger army. This bonus cannot make them more powerful than the opposing army. Only applies to units with this upgrade.
Templar sub-branch 3: Champions of the Gods: Cavalry upgrade. +2 strength.
Note: Templars are a special branch, which requires specific quests to become available. All upgrades in this branch cost 2,5d and the initial upgrade has a 2,5d upkeep.