Should all submarines actually attack when executing submarine combat or can I attack only with some to prevent expending torps? Let's say in Submarine Combat Table I get the result 2/1. Can I attack only with 2 subs and pass with third to save torpedoes?
All subs that can attack (i.e., are not Held Down) must do so. The decision to attack or not by an individual sub CO is way below the level of player control.
Which one is correct?
a) 7.4 An odd-numbered modified die roll also indicates the subs will expend their torpedoes if all attack.
b) Example: (...) and the unit counter rotated and flipped to its (1) aspect, showing that its torpedoes are expended (because the unmodified Submarine Combat roll was odd and all subs attacked).
(a) is correct. Once again, your fearless designer failed to update the Example to correspond with the rule. Originally and into this year, the rule said "unmodified." Because in many cases you won't know if the torpedoes are expended until after the ASW attacks are resolved, I finally changed it to "modified" as that result is easier to remember. Sigh...