The name of the accident method is accidents-in-terrain
.
Accidents should be restricted to definite hazardous situations, to go along
with movement constraints - for instance, carriers and battleships
in shallow water should have a small chance to hit a rock and sink.
You can specify two kinds of accident; a damaging accident, which hits the unit as if it were in combat, or a vanishing accident, in which the unit disapppears instantly.
Damaging accidents occur according to the accident-hit-chance
table, and damage the unit according to accident-damage
.
The interpretation of these is similar to their combat counterparts.
The accident-vanish-chance
table sets the probability for
the unit to simply vanish without a trace.