Certain units are attuned to a certain season; either Spring, Summer, Autumn, or Winter. They have a trait that works similarly to a Power Trait, but that handles an entirely different stat in a somewhat-different manner.

While it's the unit's preferred season, their maximum HP is boosted by a certain percentage equal to the point value of the trait. Likewise, while they're furthest from their preferred season, their maximum HP is reduced by the same percentage.

Spring is Turns 0 (which isn't played), 1, and 2; 12, 13, and 14; and so on. Elementally, it is associated with Air, while Sorcerous traditions associate it with Nature and the Thrones associate it with Growth.

Summer is Turns 3, 4, and 5; 15, 16, and 17; and so on. Elementally, it is associated with Fire, while Sorcerous traditions associate it with Nature. During this season, the world is pulled 1 point towards Heat.

Autumn or Fall is Turns 6, 7, and 8; 18, 19, and 20; and so on. Elementally, it is associated with Earth, while Sorcerous traditions and the Thrones both associate it with Death.

Winter is Turns 9, 10, and 11; 21, 22, and 23; and so on. Elementally, it is associated with Water, while Sorcerous traditions associate it with Death. During this season, the world is pulled 1 point towards Cold.

In Dominions, the year ends in Midwinter (the first instance being Turn 10); we know this because this is when Age is incremented. A turn is roughly the same as a moon or a month. So which month is assigned to which stage of the season, you might wonder? Well, January and February were originally at the end of the year (this is why February has only 28 days, by the way); assuming this holds true, a Dominions calendar looks like this:

• Turn -1: Late Winter, March ← base 1
• Turn 0: Early Spring, April
• Turn 1: Midspring, May ← the 1st turn of play
• Turn 2: Late Spring, June
• Turn 3: Early Summer, July ← base 1
• Turn 4: Midsummer, August ← base 1
• Turn 5: Late Summer, September ← base 1
• Turn 6: Early Fall, October
• Turn 7: Midfall, November
• Turn 8: Late Fall, December
• Turn 9: Early Winter, January ← base 1
• Turn 10: Midwinter, February ← base 1, everyone Ages

This makes certain things messy, such as the Summer and Winter Solstices being in Spring and Autumn (respectively), but those events aren't really referenced in-game.