Monsters are the primary source of items in Path of Exile. Understanding the mechanics that affect them can help greatly in fine tuning character experience farming. As an added bonus it can also help in hunting Path of Exile items. Check this guide for more.
How Monster Level is found for your Path of Exile items
Each area in the game has a monster level that gives a rough estimate of how difficult the area is. You don’t need special Path of Exile items to check the area’s monster level. The latter can be known by simply pressing Tab and looking at the upper right corner of the screen. Each zone has a pre-set monster level value. This goes steadily higher as players go through the game. Additionally, higher difficulty increases the monster level of an area. Monster levels range from 1 in The Twilight Strand to 68 in The Upper Sceptre of God.
Monster Level effects on your Path of Exile items
The monster level determines the item level of items dropped from chests in the area. This value is also used to determine the item level of items dropped by monsters. Normal monsters drop Path of Exile items with item level equal to the monster level. Magic monsters use monster level +1, while Rare and Unique monsters use monster level + 2. Of course, monster levels determine the monster’s stats and its rarity and affixes.