When kingdoms in Calradia go to war, their armies have two basic offensive options. They can try to attack villages and lay waste to the countryside, damaging their enemy's prestige and economy. Or, they can try to seize and hold castles or towns, taking territory. This second option can involve long, bloody sieges, but will yield more decisive results.
It is important to note that the realms of Calradia do not field standing armies, which remain in the field as long as the ruler desires. Rather, Calradian realms are protected by feudal levies comprised of the major nobles and their own retinues. Sometimes, these nobles launch their own private attacks into enemy territory, but the most decisive events will usually take place when the great hosts are assembled. The kingdom's marshall, a noble appointed by the king, will summon the host before the campaign and lead them out to battle. However, he should be careful not to keep them in the field for too long. Otherwise, the host will begin to disintegrate, as the vassals drift off to pursue their own business, and the army will be vulnerable to a counter-attack.
For this reason, the rhythm of wars in Calradia often resembles the rhythm of a duel between two individual combatants. One side will gather its strength and seek to land a blow against the enemy's territory. If the marshall spends too little time gathering the vassals, he may not be able to do any real damage. If he spends too much time, then the campaign may end before it has even begun. A large realm will have an advantage over a smaller one, just as a brawny combatant has an edge over a smaller foe, but a realm's political cohesion can also be a factor, just as a fighter with great stamina can outlast their opponent. Sometimes, the armies of two realms will meet head-on, resulting in a major battle in which both numbers and morale will decide the outcome.
Kingdoms will have imperfect intelligence about their enemies. Attacking lords will need to frequently scout enemy territory to determine which fortresses may be vulnerable. An army defending its homeland will benefit from the alarms raised by castles and towns, which broadcast intelligence about enemy movements in the area. Such intelligence will be imprecise, however, particularly when it comes to numbers. A defending force that sets out to raise a siege or rescue a village may be able to overwhelm an unprepared attacker -- or it may miscalculate, and find that it is the one to be overwhelmed. Attackers, in turn, must be careful how far they advance into enemy territory, with aggressive marshalls venturing further than cautious ones.
Players will be expected to join in their faction's military campaign, either by joining the host or by scouting ahead into enemy territory. Some players may find that their realm's marshall is too cautious, or too aggressive, for their tastes. In this case, they can intrigue with other lords to try to replace the marshall, or build support to become the marshall themselves.
Most wars are of limited duration. A king who goes to war will, for the sake of honor, feel obligated to pursue the conflict for a short while. However, unless he is soundly beating his enemy, he may soon start looking for a way out of the conflict, lest he leaves himself vulnerable to an attack by a third party. Calradia's rulers are keenly aware that today's ally may be tomorrow's enemy, and vice versa.