@Dash_Riprock:
My understanding of the rules for subs is that they are just like any other naval unit and have an attack of 2 and D of 2.
Sort of true (see below). They do attack and defend on a 2.
@Dash_Riprock:
A) If a player attacks with a sub and the defender has no destroyer, they get a 1/3 chance to instantly kill an enemy ship, before the battle starts, and without allowing that ship to ever fire back, eve if it is a BB.
In the openning fire step, attacking AND defending SUBs fire first in every roound of combat. If your force does not have a DST present, then any ship hit by the openning fore from a SUB is removed immediately before it can fire this turn. EXCEPTION: It still takes 2 hits to kill a Battleship. Also do not forget that you choose you choose your own losses, SUBs do not target specific ships (except for Kaiten N/A)
@Dash_Riprock:
B) Submerse, if no destroyer is present
True, attacking AND defendig Submarines can choose to submerge after any complete round of attack IF no enemy destroyer is present.
@Dash_Riprock:
C) They cannot hit air units, and to make sure they dont, they have to fire before everything else each round.
Not sure what you mean here. SUBs fire first because they are operating by stealth. But they are helpless against aircraft. SUBs CAN be taken as hits if you are attacked by aircraft, but the SUBs cannot fire at aircraft. So, any SUB hits MUST be taken on ships not planes. And if a SUB is attacked by air units only, it gets attacked ONCE, and then can submerge if it survives.
@Dash_Riprock:
However, by these rules, according to an odds simulator, the most effective thing to buy for a major naval battle is to simply mass subs and get no BBs and just one destroyer. Am I really seeing this right? it seems like a somewhat major imbalance.
For a straight naval battle, SUBs are tough to beat in tersm of bang for the buck. But massed SUBs w/o surface ships invites enemy air only attacks repeatedly on your fleet of SUBs. Also, SUBs are worthless except for naval warfare, so do nothing to advance your ground forces.