There are six different troop rarity tiers in the game - the base rarity of a troop usually corresponding to its overall power. Troops can be ascended to have the stats of higher rarities. A troop's rarity can be identified by its border - i.e. Commons are white, Rares are green and so on.
The rarity tiers are as follows:
- Common (the lowest value)
- Mythic (the highest value)
Common troops, being the lowest, are very basic. They only have one mana color instead of the usual two, have lower stats even when fully upgraded, and have simplistic abilities.
Rare troops are mostly a vast improvement over Commons. They have two colors, better stats, and a wide range of abilities encompassing offense, defense and strong utility options. Rare troops are often found in strong synergies with more powerful troops.
Ultra-Rare troops are a step up from Rares. Being in the middle of the pack, they are still easy enough to get to be reliable finds, but have strong enough abilities, stats and traits to be quite useful at most stages of the game. Many Ultra-Rares are strong enough to be a player's go-to troop for much of their early gameplay.
Epic troops are, once again, stronger than previous tiers. They have much higher stats but are also more expensive to upgrade (particularly for Traitstones). Each Kingdom's questline has an Epic troop at the end as a reward, so some Epics can be acquired relatively easily and are useful for some time.
Legendary troops represent most of the strongest troops. They are almost universally burdened with expensive mana costs, but their abilities are are dangerous enough to justify it. On top of their stronger abilities and higher stats, Legendary troops each also possess specific unique "Legendary traits", which are stronger than normal traits. Most end-game teams are largely made up of Legendary troops.
Mythic troops are the most powerful troops in the game. Unlike all other troops, they have three mana colors. They also have stronger 'Legendary traits'. Combined with higher stats and devastating (although costly) abilities, their downside is being excruciatingly hard to find.