CemTec is a magic Runeword created by combining a Cem Rune of Ritual and a Tec Rune of Invocation.
How to Create CemTec
You can create CemTec by adding the magic Cem Rune of Ritual and the magic Tec Rune of Invocation to a two-socketed Helm, Chest Armor, Pants, or Two-Handed Weapon.
Cem - Cast Evade. (75)
Tec - Invoke the Barbarian's Earthquake, dealing damage to enemies within. (100)
Overflow
When CemTec overflows, you receive the Tec Rune's overflow effect (Up to 100% Increased Radius) 0.5 times.
Overflow occurs when your Ritual generates more Offering than required for the Invocation. The overflow effect is proportional to the amount Offering overflows.