Dexterity
From Seeds of Time Online Wiki
Dexterity is one of the five stats into which players can invest their stat points. It is essentially the counterpart of Agility, meaning that a a high Agility can be countered with a high Dexterity and vice-versa.
Hitting or Missing
Dexterity affects your chance of successfully landing an attack. Your chance of successfully landing an attack is determined by how high your Dexterity is compared to the enemy's Agility.
Critical Hits
Critical hits are physical attacks which deal twice as much damage as usual. They are determined by how high your Dexterity is compared to the enemy's Agility. To give you an idea of how much Dexterity is important for high critical hit rates, here are some examples: critical hits occur 7.5% of the time when your Dexterity is equal to only half of your opponent's Agility, 50% of the time when your Dexterity is about 3.33x your opponent's Agility, and 100% of the time when your Dexterity is at least about 6.66x your opponent's Agility.

