A battle opens with the volley: every ranged company on both sides looses once, before the lines meet. Then the lines clash, up to 7 times. If both armies still stand at the end, night falls and the field stays with the defender.
Each company brings its attack and defense to every clash: attackers lean on attack, defenders on defense. That strength is scaled by the company's remaining health, its veterancy (+12% per rank, two ranks), the ground, and the modifiers below. A hero adds their might, growing with level. Each clash then deals casualties in proportion to power, swinging about ±15% either way.
Leaving the field
From the second clash on, a side that is badly outmatched withdraws rather than dying where it stands. Wary armies leave early (under 80% of enemy strength), measured armies at 50%, bold armies only at 28%. Withdrawing costs one parting blow at half strength. Neutral defenders and the unyielding never leave.
A beaten army falls back to a friendly neighboring province if one exists. If none does, it disperses: heroes try to slip away home, wounded, and some do not make it.
What bends the odds
The ground itself. Deepwood +15%, Highdowns +15%, Crags +30%, Mistmoor +10% for the defenders.
Walls. Palisade +20%, Stone Walls +35%, High Keep +50%, for the defenders, on their own land. One company of Siegeworks in the attack levels all of it.
Crossing a river. The attackers fight at −15%. Flying companies ignore rivers.
Landing from ships. The attackers fight at −15%.
Charge. +20% in the first clash, on open ground (Meadowlands or Highdowns), unless the enemy fields a bracing company, which cancels it.
Ambush. +25% in the first clash, when attacking.
Brace. +10% when defending, and enemy charges break on the spears.
Terror. The enemy fights at −8%, unless they also field terror, an unyielding company, or a lord who does not scare.
Leadership. Your best hero adds +2% per point of leadership, up to +30%.
Ember Adepts. +4% per company of casters, up to +12%, and they let battle-spells weave (the Emberlight chapter has the spellbook).
Stance. Bold fights at +10%. Wary fights at −12%.
Emberlight fervor. An attacker may burn 6 raw Emberlight before committing: the whole assault fights at +12%. Always offered in the odds preview, never automatic.
Armor. An armored company turns aside 15% of the hits that reach it.
After the battle
Surviving companies on the winning side have a fair chance to season into veterans. Heroes on both sides risk wounds or death: more when the day was lost, more when the casualties ran high, less if they carry a death-save. Heroes also grow: experience flows from the enemy hits your side dealt.
Every one of these numbers appears by name in the odds preview before you commit a single soldier. If the preview does not list it, it is not in the battle.
Osperan: I have chronicled four hundred battles. The ones worth retelling were decided before the first arrow, by someone reading the ground, and someone else declining to.