BacTun is a legendary Runeword created by combining a Bac Rune of Ritual and a Tun Rune of Invocation.
How to Create BacTun
You can create BacTun by adding the legendary Bac Rune of Ritual and the magic Tun Rune of Invocation to a two-socketed Helm,
Chest Armor,
Pants, or
Two-Handed Weapon.


Overflow
When BacTun overflows, you receive the Tun Rune's overflow effect (Increased Grenades Spawned) 1 times.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.