Combat takes place usually when there is a force attacking and a force defending. Sometimes these conflicts can be incredibly complex as multiple factions rally against each other based on defense pacts and alliances which determine how everyone will pick their sides.
Being reduced to 0 HP scatters/destroys the Troop.
Troops must be raised before they can be used, and they must be raised at a settlement.
Combat is handled in one of two ways, "Swift Deployment" or "Mass Deployment".
Swift Deployment is used outside of war, and uses scouts for the majority of combat. These battles are meant to be short skirmishes typically with only a few individuals, most of which are less well equipped than an army (but still well enough to defend themselves). These fights are meant to be resolved in a roll or two as two units clash, and so as to not bog down game time with every native or bandit encounter.
Mass Deployment is used in cases for massive battles with multiple battalions of troops engaging in one prolonged battle. These fights are usually reserved for when all players in the game are involved in a fight, so as to keep from players not being included in a combat map and thus waiting for extended periods of time just for their turn to come about.
Swift Deployment rules are simple and concise, meant to keep kingdom turns flowing alongside combat. Outside of war, scouts are fielded to the map in place of troops. Scouts perform a variety of duties which aid in out of war activities such as preventing monster incursions, removing banditry, and clearing out unruly natives.
Scouts can be created and placed adjacent to any Settlement, and cost 5 Wealth in order to create and cost 1 Wealth as upkeep.
If a scout is faced with combat such as from bandits or the like, they must make a Military check with a DC determined by the obstacle. Typically bandits are DC 17, natives are DC 20, and monsters DC 24 to 28. On a successful roll, they deal with the threat. On a failure, the scouts are routed and destroyed.
If war is declared, scouts return home and no longer cost their upkeep to maintain. After which, the focus should be changed to troops and starting combat.
Mass Deployment uses a separate combat map, and uses Troops as opposed to Scouts when engaging in battle. These troops represent battalions of men fighting together rather than one individual character like in the normal combat of Fourth Crusade.
Initiative is rolled as a 3d10 roll (which may be modified by certain applicable traits and abilities).
Troops when raised on the Overland map move 1 square per turn, and are able to occupy the same space as other friendly Troops. Battle occurs when two enemy Troops would occupy the same square. Other players wishing to participate in a battle they aren't near can field a single Troop on the battlefield from their army - this is to prevent players from being bored while one player engages in battles on their turn. This can be done a number of times outside their own turn equal to their Military attribute (minimum of 1).
Adjacent Troops - enemy or ally - are able to join a battle. They are still limited to bringing a number of Troops to a battle equal to their Military attribute however. For example, if a Troop of 8 enters a fight and is now occupying the same space as their enemy, but they're only able to field 6 Troops due to having a Military of 6, 2 of their Troops return to their origin square while the other 6 join the battle. If an ally had Troops adjacent, their own Troops can join, but are beholden to their own limit based on their Military attribute.
Alliances
If the player characters have massive alliances between each other or would otherwise field massive amounts of troops in a single battle, it is recommended to multiply the enemies' troops allowed per battle accordingly. For example, if the players make up three armies and are only fighting a single kingdom's military, you can multiply the troops they're allowed to bring into the fight by x1.5 or x2, especially if fights begin to become lopsided due to these sorts of player-based alliances. It's not recommended to try to forcibly break these alliances up however, instead - alter the threat to cater to their new power as a collective.
Laying siege to fortifications and buildings may be necessary during combat as an attacker, and defending such fortifications and cities is necessary as the defending side. Fortifications can be erected in the middle of combat, but are often less reliable than those of forts or cities.
Against buildings and cities, laying siege means trying to defeat the inhabitants inside whether that be starving them to death, surrender, or outright assaulting the building in order to force them into submission.
Creating a blockade - be it naval or land-based - cuts off those within the blockade from vital resources by surrounding them with troops (or in the case of the ocean, ships).
In order to initiate a blockade, the attacker must have a Troop adjacent to the Settlement. By initiating a blockade, you prevent the settlement from receiving food or resources, intending to make them easier to fight or force a surrender without combat.
For every turn which a blockade remains in place, roll a Military check against the opponent's Economy. On a successful Military check, the blockade is successful for that turn; the square which holds the settlement is not counted when producing tax, and the buildings in the settlement are unable to perform their normal functions (unless otherwise stated).
Troops raised by the defender on the blockaded settlement suffer a -2 penalty to all checks if the Military check from the attacker succeeded.
If a settlement remains blockaded for a number of turns based on its size, the blockade successfully causes the settlement to be captured by the attacker. They have the choice to raze the city, or occupy it. Breaching (see below) can help reduce the amount of turns it takes before a settlement capitulates.
Thorpe: 1 turn
Hamlet: 2 turns
Village: 3 turns
Small Town: 4 turns
Large Town: 6 turns
Small City: 8 turns
Large City: 12 turns
Metropolis: 16 turns
Razing a city produces 10 Wealth for the attackers, the defender loses 10 Wealth, and they suffer a -1 penalty to Stability until the end of the war (if any, otherwise it lasts until their next turn). In addition, a number of buildings equal to the attackers Military can be destroyed if they wish.
Occupying a city produces no wealth, however the settlement and all adjacent squares (except for squares which house another settlement) are considered occupied by the attacker. While occupied, the settlement only produces half of its value in tax, however Military & Law Enforcement buildings are unable to be used.
Directly assaulting the foes is a much riskier task and can result in many more deaths, but can result in a quicker and more violent end to the siege. First the attacker must find a way to get around or break through the defender's defenses, and then launch their attack once this is done.
In order to attempt an assault, the attacker's Troops must be positioned on the settlement's square. A battle using Mass Deployment occurs, and if the attacker wins the assault, they reduce the amount of turns until the enemy capitulates by the attacker's Military minus the defender's Stability (minimum of 1).