Royal Warfare strategy guide

Units will act automatically on the battlefield. Priests heal injured soldiers. Warriors block incoming enemies.
Each soldier has two unique abilities, and soldiers decide themselves when to use them.

Combine abilities for a maximum effect. There are lots of combinations, try to discover them all.

Don't upgrade units to the second tier if you need some abilities, that only first tier units can perform.

Place archers at the first line, and warriors at the second, right behind them. When enemies come closer, warriors will charge and block the incoming enemy warriors.

Unit can't be attacked by melee against more than 6 enemies.

If a unit withdraws from the fight, he will get an instant backstab hit. It will not happen if two or more allies attack same enemy. A unit can't withdraw from battle, if he is surrounded by fast-moving enemies.

All units have armor ratings. Units with better armor receive less damage from swords and arrows. The higher the value, the less damage it receives.
Armor piercing reduces the armor effect. If a unit's AP is higher than the target's armor, no damage reduction will occur.

Warriors will charge the incoming forces by themselves and get involved in combat. They move slowly, so use them for blocking enemies. Try not to let Knights fight against enemies with high armor piercing rate.

Archers deal immense damage using their arrows to unarmored targets, and their mobility grants them an ability to evade enemy attackers. If there's no fast moving enemies in the incoming wave, you can move archers and snipers far away from the warriors, and just step back after each salvo.

Mages throw magic bolts and cast spells. Magic bolts bypass any armor, but the target's resistance blocks some damage. Use mages against armored targets. Also, some spells work great against large groups of enemies.

Some spells have area of effect, so for a better result target the center of a group of enemies.

Priests can heal injured soldiers and pray for different blessings. Protect them well because they are very slow and weak and will certainly die in close combat. But they strongly affect the battle and their presence is vital.

Thieves are a fast and mobile force. Their agility grants them the ability to withdraw from battle without getting a backstab hit, so use thieves for raiding enemy archers and casters, or for distracting the incoming forces. The best tactic for them is hit-and-run.