MCRExperience

The varying levels of experience are as follows:
Green: 1
Regular: 2-3
Hardened: 4-5
Veteran: 6-7
Elite: 8-9
Legendary: 10+

Experience is gained just like D&D Heroes do, except for a unit of soldiers and not just a single Hero. This accounts for not just the experience of the troops within the unit, but for the ability of the troops to train newcomers to the unit. If a Hardened unit takes on new members to fill their ranks, the unit is still treated as Hardened because the troops will be educating their new arrivals and protecting them, and more often than not any casualties incurred are on the less experienced soldiers.

As units level, they gain valuable combat bonuses. The table below details the bonuses more fully:

Level Experience Needed To-Hit Bonus Damage Bonus Defense Bonus
1 0 +0 +0 +0
2 1000 +1 +1 +1
3 2250 +1 +1 +1
4 3750 +2 +2 +2
5 5500 +2 +2 +2
6 7500 +3 +3 +3
7 10000 +3 +3 +3
8 13000 +4 +4 +4
9 16500 +4 +4 +4
10 20500 +5 +5 +5

Troops cannot become legendary through raw experience and will have bonuses to reflect their legendary status when the time comes.

MCRExperience

Alendar & Volinar FrontalMonk