Indeterminism reduces predictability and amount of information available to player(contrast with complete information games like chess). Source of Indeterminism
1.Invisible units/characters or projectiles.
2.Fog of War and unexplored territory.
3.Random chance to miss or fail attack.
4.Random cooldown delays.
5.Random range of values:e.g. damage 4-10
6.Random events/spells/effects that have a chance to fail.
7.Random initial stats of units: i.e. units of one type are not completely identical.
8.Unit AI has random parameters.