+8. Still more BSD-Trek: we now have a weighted damage table. Quoth
+Eric Allman in the code of BSD-Trek: "Under certain conditions you can
+get a critical hit. This sort of hit damages devices. The
+probability that a given device is damaged depends on the device.
+Well protected devices (such as the computer, which is in the core of
+the ship and has considerable redundancy) almost never get damaged,
+whereas devices which are exposed (such as the warp engines) or which
+are particularly delicate (such as the transporter) have a much higher
+probability of being damaged."
+
+This is one place where OPTION_PLAIN does not restore the original
+behavior, which was equiprobable damage across all devices. If we
+wanted that, we'd return randrange(NDEVICES) and have done with it.
+Also, in the original game, DNAVSYS and DCOMPTR were the same device.
+
+Instead, we use a table of weights similar to the one from BSD Trek.
+BSD doesn't have the shuttle, shield controller, death ray, or probes.
+We don't have a cloaking device. The shuttle got the allocation for
+the cloaking device, then we shaved a half-percent off everything to
+have some weight to give DSHCTRL/DDRAY/DDSP.
+