Beam Hits on 4+ on the initial strike and all further rolls. So the 2nd, 3rd, 4th etc. all will hit on a 4+. Means more hits on large vessels then in 1st ed (what means more crits) and less hits on Hull 4 or 5.
The skirmish ships get a boost, Battle and above a downgrade.
Agile:
If your ship...