Hier steht:

Engineering Upgrade (Passive)
Improves other Tinker abilities with each level learned:

Cluster Rockets - Larger Area
Pocket Factory - Builds Clockwerk Goblins more quickly
Robo-Goblin - Increases armor and Strength; enhances Demolish.

Also gives bonus damage and increases the Tinker's movement speed.

Also: sehr geiler Skill, würd ich mal sagen. Spiel zwar schon lange kein W3 mehr, würde den aber dem Tinker sicher skillen!