In Dominions 4, units are either troops or commanders. You give all your commanders orders each month, and optionally assign them troops to bring with them; if the commander is engaged in combat, all of his troops fight alongside him according to their script.
As the only units that you can directly order, commanders are a necessary part of any nation. They may be:
- Priests: commanders with holy levels can preach, construct temples, and cast battlefield spells;
- Mages: commanders with magic paths can research, build labs, cast rituals and battlefield spells, and search for sites
- Stealthy: commanders with stealth can sneak if the only troops they command are also stealthy
- Leaders: most commanders can lead troops, and many can also lead magic beings and undead or demons.
- Gem-holders: commanders can carry gems and blood slaves
- Item-bearers: commanders can be given magic items
- Prophets: you may designate one commander as your prophet, which promotes it to a Holy 3 priest (or +1 priest level if it already is) and gives it some special powers
You can recruit one commander per province per turn. (Slow-to-recruit commanders take two turns.) As with units, noncapital provinces provide access to independents based on their poptype, and provinces with a fort allow access to most of your national commanders.
Commanders can also be given more detailed scripts in combat than units can. Otherwise, commanders have battlefield statistics and act in combat just as troops do.