Sneax and company fought their first dragon last night. In the D&D Starter Set there's an adventure called The Lost Mine of Phandelver, and in it, you're trying to rescue a trio of dwarfs, the Rockseekers, and help them reopen an ancient dwarven mine. One of the them gets captured and taken to Cragmaw Castle, but you don't know where the castle is, you have to seek out the druid Reidoth to get directions. Reidoth will show you where the castle is--he'll even lead you to the ancient mine--but his price is steep. He wants you to chase off a young green dragon that's taken up residence in the ruins of a wizard's tower in the abandoned town of Thundertree. This presents something of a problem.
The dragon is holed up inside a 15' round room, a tower that's 40' high and which has an open roof. Perfect home for a dragon, really. There's a tiny (10' square) one-room cottage attached to the side of the tower, which is also more or less intact. The whole thing is atop a tree-covered hill with a single trail leading up.
Yes, I drew that to scale for our mini's.
The problem with this set up is that a green dragon's breath is a 60' cone of very potent poison. It's non-persistent, thank God, but still... I figured that as soon as Sneax and company hit the cottage, the dragon would fill the place with poison, and that would be that.
The company surprised me. The key was 5e's rule letting you move, attack, and then finish your move.
My daughter's Rogue Sneax tried to sneak in and scout the area, but she failed her Stealth check. The dragon started talking smack, but the Players won Initiative, so my Fighter Anzlo charged past Sneax and clobbered the dragon with his magic sword before moving further into the room. Sneax then got in a Sneak Attack and disengaged (back out the cottage door), and then my wife's Wizard Katriness dashed in, fired off a barrage of Magic Missiles (cast as a 2nd Level Spell, before also dashing back out. This left the dragon wounded and angry but facing only Anzlo in the tower. The dragon's Claw/Claw/Bite attack landed only one hit against Anzlo's heavy armor, a Claw attack. Then the hit-and-run tactics went another round. Everybody kept hitting the dragon, which was extremely lucky.
After two rounds, the dragon was nearly bloodied. He leaped up to the top of the tower (drawing an OA which actually DID bloody it), saw the PCs outside, and hit the group of them with his breath weapon. Good thing my daughter's Cleric Jayditha had cast Aid onthe squishier members of the company before the fight. Sneax and Katriness both failed their Constitution Saving Throws and dropped from 23 to -20 hit points in an instant. Jayditha made her Constitution Saving Throw, stayed up at 5 hp, and used Channel Divinity: Preserve Life to wake the party back up. Then Anzlo emerged out the front door relatively unscathed, and the dragon--seeing that it was already bloody and that it's best shot hadn't killed anyone--ran for it.
Now the party has more gold than it can readily use, and Anzlo has both a magic sword and a magic axe. Gotta figure out how to Transfer Enchantments from one of Anzlo's weapons onto Sneax's short sword.