When it is your turn, WL will try to execute your next order. However, if the next order cannot be executed for whatever reason (most commonly because you've already lost the territory where you tried to attack from), WL skips that order and goes on to the next, until it finds an order which
can be executed.
An important detail is that orders which, for whatever reason, work out to having zero armies
actually do something count as "not executable" in this sense (a common case: attacking from a territory with exactly one army on it). Note this is
not the same as
affecting zero armies. A great example is indeed the "trick" which started this thread; the failed transfer-only order does
affect those armies (they get marked as "used" and cannot be used again this turn), but they didn't
do anything (they simply sat where they were).
For completeness' sake, the reason to mark armies as used when their transfer-only (or, attack-only) didn't happen is to prevent a dirty trick. Let's say you're in Northern Canada (Yukon, NW Territories and Nunavut) and you're attacking southward (British Columbia and Alberta), with these orders:
- Yukon attacks BC (with all armies)
- Nunavut attacks Alberta (with all armies)
- NW Territories performs an attack-only against BC (with 50% of its armies)
- NW Territories attacks Alberta (with all remaining armies)
It is our job as players to predict whether our opponent will try to defend both territories or just the one they consider most important. If the 50% armies from the first NW Territories attack are not marked as used, we can be lazy and enter a strategy that works equally well whether the opponent tries to defend both of them (NW Territories attacks both of them), or sacrifices BC in an attempt to at least keep Alberta (the sacrifice is probably in vain; NW Territories attacks with all its armies,
knowing that BC has already fallen).
however you can also do them in games without multi attack for your entertainment
Delay orders need to be (at least) one army to actually delay anything, and they can indeed be used in all game types... and even earn you three achievements:
"Issue at least X orders of one army each, to delay a later attack (last attack must be 10+)"
Edited 6/10/2015 14:59:35