My party's Cleric has just picked up Augury. It's clearly a spell that garners some understandable confusion, but I don't think this precise question's been asked before.
How should I, as DM, answer Augury when the good or bad outcomes of a proposed course of action hinge on a skill check, which is random?
To provide a concrete example, suppose the party need to recover some battle plans from within an enemy encampment. In the dead of night, the Cleric casts Augury, proposing: "The rogue sneaks past the sentries and takes it from the command tent". It's a fine plan, one I expected them to try, and it will work perfectly if the Rogue rolls at least an 11 on their stealth check – a 50% chance. But if they roll under, the alarm will be raised, and the Rogue will likely be captured.
This isn't "Nothing", and it isn't "Weal-and-Woe" – the result is definitely one of Good or Bad, and it isn't both. It also isn't contingent on any subsequent effects that would change the outcome. So how should I answer?
Best Answer
Augury assumes you will do what you set out to
Augury doesn't tell the future - it tells you what the ultimate outcome of a particular course of action will be. The important parts of the spell description:
And:
The result of using Augury on a plan of attempting to sneak past the guards should likely be nothing - the omen does not know if you will succeed or not.
However, the result of using Augury on a plan of sneaking past the guards to steal battle plans should likely be weal. If you sneak past the guards and get the battle plans, you'll have an advantage in the coming fight! Seems pretty straightforward.
But wait! The result could instead be woe! This might indicate that it's worthless to sneak past the guards as the battle plans you learned of are fakes!
It could have a result of weal and woe! You'll successfully steal the plans and have an advantage in the coming fight, but you haven't figured out yet that you're really working for the villain!
Help your players craft a good query
As a DM, if your players are trying to use Augury on a roll-dependent outcome, be willing to help them modify the request to be what they really want to know.
Ultimately it's up to the DM
nitsua60 makes an excellent point in the original question about Augury - it's a different sort of spell and wide open for interpretation.