Artifacts are special items that are placed in a special new slot on your character. They grant special bonuses to your character on top of the ones already granted by your previous equipment. Finding an artifact is hard (they drop very rarely compared to other items in the game), but you can create one if you find an Enchanter and ask him to make you one.
For the Enchanter to create one for you, you will need a recipe (Arcane Formula) though. With the Arcane Formula, the correct amount of money and the reagents, the Enchanter will create the Artifact for you.
They come in three types: lesser, greater and divine. Greater artifacts normally require lesser artifacts as ingredients and divine artifacts normally require greater artifacts.
Some greater artifacts and most divine ones grants the wearer a specific skill, that are activated in different ways:
On attack: have a chance to activate when you attack.
On low health: always activate when you are low on life
On low energy: always activate when you are low on energy
On hit: have a chance to activate when you're hit
On ranged hit: have a chance to activate when you're hit by projectiles
On melee hit: have a chance to activate when you're hit on melee
All of these skills have a cooldown timer, most of them very long, so they won't activate that often.
Requires: Titan Quest: Immortal Throne, Ragnarok