Optimizing 5e Dragons

[tortor]

Fun thought exercise for the hivemind,
Say you have a party of fully min maxed characters and you wanted to present a formidable, optimized dragon fight. Pulling out all the stops. How would you Optimize an adult 5e dragon (your choice of color~)

[Clone]

What level? Depending on that would drastically change the fight.

Assuming level 5/6, I'd have a Young Black Dragon coupled with some clay golems, maybe a black Half-Dragon too. Also a Cleric worshiping said Black Dragon to heal it and bless it, helping saves. That may be a tad overkill though.

[jitzul]

Give them magic.

[MrStabby]

The dragon comes for them in the night. The dragon watches and waits till the party is tired and depleted from a long day of adventuring and it attacks when they set up camp and take off their heavy armour but before they get any benefit from a rest. Probably night has fallen so those without darkvision will need to take a turn lighting a torch or casting a lighting spell

The Dragon opens with a breath attack and lifts off outside of melee range. Ideally finding some cover so PCs will have to circle round to get a clear shot - this should split the group. Next turn dragon repeats breath attack if it has recharged else it grapples a player and flies off, making bite attacks as it goes. Dragons are fast and can easily fly outside of most PCs darkvision range. Next turn dragon gains altitude, makes its attacks against the PC it has grappled and then drops them for a lot of bonus falling damage. If they live finish them off dragon vs one isolated PC. Else wait for breath weapon to recharge and repeat.

[SilverStud]

Tough fights are all about the behavior of the monsters! If you ever have an "easy" fight against something like a dragon, I'm willing to bet your DM either
a) Let you enact a sweet plan to ambush it somehow (or something similar)
or
b) Played the dragon like a vicious XP balloon: it approaches to melee range and uses multiattack, maybe breath weapon.

So yeah, MrStabby's method is awesome. Have a dragon that fully intends to kill them, and have it watch and wait for the opportune moment. This works with any dragon, but greens give you the best excuse because their forests allow them to watch the party's every move without being present. Here are some fun ideas for an ambush:

When the party gets to the magical hedges, the green dragon toys with them by biting from the other side of the hedges and breathing poison through the leaves

The party is exploring ancient desert ruins when the blue dragon suddenly collapses the whole thing on them!!!

Avalanche + White Dragon

Black dragon lures the party to his "lair," which really isn't his lair but a portion of swamp that is particularly nasty and/or infested with black puddings.

For red dragons, just run an epic fight around a castle with the tactics MrStabby describes. Red dragons are so iconic you can run them straight! :P

[NecroDancer]

Variant spellcasting rules help (I believe an ancient red can cast antimagic feild).

Giving a dragon the shadow template and some shadow minions is a good idea as well (5 shadows took down an 8th level paladin with a bunch of anti-undead items).

[Unoriginal]

Question is, do you want an epic dragon fight, or a fight where the dragon has the most chance to win?

For a fight where the dragon has the most chance to win:

-Be dragon

-Figure out where the MCs are.

-Have them find rumors about your riches-filled lair being around (while it is not)

-Send a few big monsters or aggressive animals after them all day. Enough they have to spend ressources on, not enough to discourage them. Herd them toward the path you want them to take.

-Wait for the PCs to go on a narrow, if solid rope bridge you've had prepared in advance

-Breath on the PCs and the bridge while they're all in a line

-Watch PCs fall as the bridge is destroyed

-Kill the PCs that can fly

-Have stakes and tough monsters waiting for the falling PCs below.

[Strill]

Be blue dragon.

Use burrow speed to burrow into the sand.

Pop out of the sand and blast the party with lightning breath.

Burrow back into the sand.

Wait 6 turns.

Repeat.