Also, for a Call of Duty map or Battlefield 2 or even WoW, you can create a unit that looks like a symbol near a unit that had killed enough people to rank up or anything. Just like in WoW... honor kills. One of these appears when you kill an enabled player on the opposite "team".
You see them, on war games like Command & Conquer. When a unit kills someone, one of these appear of them. Then if they get another kill, two will appear, than 3 and so on.
They're pretty much used to see who has the most kills, or for warcraft you could use something like: If a unit reaches level 3 they upgrade into a better unit.
Could be used for fantasy maps but its mainly more situated around modern war or whatever.