D&D 5E Hey I need help!

[akr71]

So you need a fool-proof plan against an unknown opponent or opponents in an unknown terrain, but likely a castle or keep...

Cast wish or pray to the gods to intervene. I don't have a fool-proof plane that covers all possible scenarios.

 

[DemoMonkey]

I’ll be happy to help you.

First, you have 4 characters and an army, right?

Step 1: Dress up 4 people in your army to look like you and your 3 allies. Do not tell the DM you are doing it.
Step 2: Command your army to attack the castle. Hopefully the defenders will waste lots of attacks and spells killing the 4 mooks they THINK are you and your allies. Tell your DM “Oh no, you are killing my characters!”
Step 3: Using Invisibility, Illusions or just sneakiness have your character sneak into the castle and steal the artifact during the distraction. Do not tell your DM you are doing it.
Step 4: When your army is destroyed and your decoys murdered and the DM is gloating over how he "pwned" you, THEN tell him “Nuh uh. Those were decoys and I already stole the artifact. Lulz!” (or your own words to that effect).
Step 5: You win D&D.