-The Frost Grenade, as a ranged Area-Effect root, provides numerous opportunities for clever usage to the Mage. It can be used defensively, as a method of escaping when mana has been depleted, or offensively, as a method of trapping targets in position to begin ranged Area Effect bombardments via Flamestrike or Blizzard (or perhaps even an Improved Blizzard). Furthermore, the root is a Frozen effect, meaning builds using the Shatter talent in the Frost tree gain an additional opener for massive critical spell blasts.
-The self-damage caused by Goblin Sapper Charges can be partially or fully negated by a Fire Ward, effectively giving us a low-mana version of Blast Wave. (Although the sapper charges will not Ignite the target on a critical hit.)
-Targets afflicted with Improved Scorch will take additional fire damage from engineered explosives. As with sapper charges, though, critical bomb blasts will not Ignite.
---TO BE DOUBLECHECKED---
Can engineered explosives still *get* critical hits even?