Given the time Traveller was written, the concept of it being anything but hot fusion would be foreign, and certainly fusion guns and fusion drives are hot fusion. The jury isn't still out on cold fusion; it's quite clearly bogus (at least, in the real universe. Traveller-style nuclear dampers could plausibly enable cold fusion).Did Marc ever say if Fusion power in Traveller was Hot Fusion or Cold Fusion ( jury is still out on that one, I know)? I seem to remember that Fusion+ in T4 was cold fusion.