Edena_of_Neith said:
Me: The dragon is coming.
Party: That's a CR 20 encounter! We're CR 5.
Me: Tough.
Party: What do we do?!
Me: (raises eyebrows) Run? Hide? Fight? I do hope you make up your minds quickly ...
Party: It's not balanced!
Me: Would you have preferred the 5 beholders I was considering? You ought to thank your lucky stars it's only a young dragon. Now, you have about 10 seconds to do something, before I rule you lose initiative to said dragon ... 10, 9, 8, 7, 6, 5 ...
Party: Uh ... ok ... we ...
Me: 4, 3, 2 ...
Party: We act out Operation 21! (pre-planned set of actions for just such an emergency.)
Me: Ok. On with the game ...
Operation 21 - Everyone scatter, meet back up at last nights camp sight. If the Dragon hits your best friend, know that he's dead and you will only be joining him.
So the party scatters, six different directions, the ranger goes for the clump of trees to the North, but the dragon is after the southern traveling Halfling that took the poison of invisibility and is headed for that Dire Weasel hole. Swoop down, and at the end of the Halflings double 20' (40') move rolls a 36 on his to hit.
He swoops back around looking for the Elf in the robe with the spell book and the magic components. He notices the Gnome with the horn as he scrambles east. The wizard is north east. He bites the Halfling in half as the little guy stabs him in the cheek with his dagger- oh, isn't that cute

. He claws at the Elf, impacting and cutting through the Elf's Shield spell and Mage Armor like it wasn't even there (28 on his to hit). The Elf staggers but doesn't drop. The dragon lands as he turns a 180. The Wizard throws a lightning bolt at the dragon (26 save). Ouch, couple more dice of damage, still in the 200 hp range. The wizard dies with the next bite.
The Gnome sees a Dire Weasel hole and dives in, only to find himself face to face with a.... ya, you guessed it, a Dire Weasel. The Bard starts singing- "between teeth, I am about to be poo-" The dragon looks in as the Gnome is fending off the weasel, smiles and vows to return for one of them.
The human fighter in her scale mail and shield turns to face the swooping dragon, raises her shield- "come to the ground and fight me!"
From 20' away the dragon takes a dramatic breath, the fighter charges, and the dragon's fire broils her in her armor. She staggers, some how still alive, rolls a natural 20 with her axe, but only a 19 against the dragons Mage Armor + Shield + Natural Armor = normal hit. A dozen more hp down on the dragon. The fighter snarls ripping her axe free and the dragon hits her with the back of his fist, giving the fighter an AoO (miss), and enough subduel damage to KO the once lovely fighter.
Whose next? The human cleric flees fast a foot, two rounds on the wing the dragon lands before the man with the fighter's limp body in his claws- "I show you- mercy." The fighter falls to the ground. "For her life I want your meet point!"
"I-"
"You will lie-" the dragon roosts him too.
He leaps to the air, going towards the clump of trees back int he distance. The ranger is hiding well, but not well enough. The dragon starts strafing the forest, burning trees, the rangers wields his bow with accuracy, and manages to bury one arrow quite expertly into the dragon's hide (hay, 2 natural 20s in one "fight" isn't unheard of).
Finally the trees are ablaze, driving the ranger into the open.
A sword in one hand and an axe in the other- "we should have stayed together."
"You know aside from all the flying, this battle would have gone the same way- make a new character this is a TPK."
And so the "tough" GM goes.