Hospital

Brings some of the dead back. Up to 40% of what a village loses in a battle at home arrives wounded instead of dead, and heals in a queue of its own.

• Healing a unit costs what training it would have cost, so what the Hospital saves is time, not resources - and the time it saves is half, because healing runs at twice training speed.
• One queue for both: infantry and cavalry wait in the same line rather than having one each.
• Siege engines, settlers, administrators and the hero are never wounded, and nor is anything from a village that had no Hospital when the battle was fought. Building it afterwards saves nothing.
• Nothing that hurries training hurries healing - not a Trainer artefact, not a helmet, not Alliance Recruitment. The only lever is the building's own level.
• Wounded troops left out of the queue die at 10% a day, so the queue is a deadline rather than a store.
• It runs beside the Barracks and the Stable rather than competing with them, so a village with all three replaces losses faster than it can train.

The maths. Healing runs on the training curve at half speed: base training time x 0.9^(level - 1), divided by the world's speed, then halved. A Legionnaire that takes 0:10:20 to train at level 10 takes 0:05:10 to heal at that level. Nothing that speeds training up touches it - not an artefact, not a helmet, not Alliance Recruitment, not the Romans' Horse Drinking Trough - which is the easiest thing here to get wrong. Infantry and cavalry share one queue, and siege, settlers, administrators and the hero are never wounded at all.

Strategy. A few early levels can be valuable for active raiders recovering routine casualties; higher levels become more important as battle losses grow.