I should have remembered 'Mote', thank you. The first one to overload the others' shield won. Lasers, nuclear-tipped torpedos, all add to the energy budget.

I should have remembered 'Mote', thank you. The first one to overload the others' shield won. Lasers, nuclear-tipped torpedos, all add to the energy budget. Pent up energy cascades _in_ when your field collapses. 'Brenda' by Larry Niven, set in the CoDo Universe, has as it's backstory the cleanup job after a really large fleet engagement.