Experience level indicates the power of a unit relative to other units of the same type. Units advance their experience level by gaining experience.
A hero's experience level can be as low as 1, although heroes may be recruited at a higher level. Heroes and leaders have a maximum level of 30 in scenarios, and a varying maximum level from 3 to 30 in a campaign, increasing as the campaign progresses. Other units have only three levels: inexperienced (when first produced), experienced (denoted by a silver medallion), and veteran (denoted by a gold medallion).
When a unit attains a higher experience level, they receive additional abilities and/or increase their stats. Heroes are able to choose how their abilities and stats improve, but other units are improved based solely on their unit type. Heroes gain 10 skill points to spend on abilities or stats per experience level, which is added to their base of 25 skill points at level 1 (for a more complete breakdown of how spending skill points works, see the hero page). Non-hero units will always increase their Attack, Defense and Health by 1 when they reach "experienced", and their Damage, Resistance and Health by 1 when they reach "veteran", though they may also gain some additional abilities such as archer units gaining (or improving) Marksmanship. A hero's upkeep increases by 
2 when they go up one experience level; other units' upkeep remain the same regardless of experience level.
Difference from Unit Level[]
Experience level is easily confused with unit level, though they are quite different. Some of the main differences are
- Unit level describes a unit's strength relative to other unit types; experience level describes a unit's strength relative to the same type.
- Unit level only applies to non-hero units; experience level applies to all units.
- Unit level never changes; experience level may increase as experience is gained.