Core · Weapon · Rules

You may discard any number of successful hits from one or more instances of this Weapon to add X E to another remaining hit. For example, two identical E2 Cannons with Focus 1 and 4 attacks each score a total of 6 hits. Their player chooses to discard 4 of these hits to add 2 Energy to each of the remaining hits, resulting in two E4 hits.

Source: Dropzone Commander Rulebook 3.02 · 3.02 · p. 49 · weapon-special-rules