After a battle, wounded troops are sent to the Hospital to be healed and then return to the Reviewing Stand. The capacity of wounded troops at the Hospital is decided by the Hospital Lv.

If the number of wounded troops from battle exceeds the current capacity of the Hospital, 

the exceeded number of them will die due to no treatment.

So, remember to upgrade your Hospital to have enough space for wounded troops before you go into battle.

■ How to Upgrade the Hospital

- [Main Screen] > [My Dominion] > [Hospital] > [Upgrade]