Huge Dragon (Chromatic), Lawful Evil
- AC
- 19
- Initiative
- +11 (21)
- HP
- 207 (18d12+90)
- Speed
- 40 ft., Fly 80 ft., Swim 40 ft.
| Score | Mod | Save | |
|---|---|---|---|
| STR | 23 | +6 | +6 |
| DEX | 12 | +1 | +6 |
| CON | 21 | +5 | +5 |
| INT | 18 | +4 | +4 |
| WIS | 15 | +2 | +7 |
| CHA | 18 | +4 | +4 |
Traits
Amphibious. The dragon can breathe air and water.
Legendary Resistance (3/Day, or 4/Day in Lair). If the dragon fails a saving throw, it can choose to succeed instead.
Actions
Multiattack. The dragon makes three Rend attacks. It can replace one attack with a use of Spellcasting to cast Mind Spike (level 3 version).
Rend. Melee Attack Roll: +11, reach 10 ft. Hit: 15 (2d8+6) Slashing damage plus 7 (2d6) Poison damage.
Poison Breath (Recharge 5-6). Constitution Saving Throw: DC 18, each creature in a 60-foot Cone. Failure: 56 (16d6) Poison damage. Success: Half damage.
Spellcasting. The dragon casts one of the following spells, requiring no Material components and using Charisma as the spellcasting ability (spell save DC 17):
At Will: Detect Magic, Mind Spike (level 3 version)
1/Day: Geas
Legendary Actions
Adult Green Dragon can take 3 Legendary Actions per round, regaining all uses at the start of its turn.
Mind Invasion. The dragon uses Spellcasting to cast Mind Spike (level 3 version).
Noxious Miasma. Constitution Saving Throw: DC 17, each creature in a 20-foot-radius Sphere centered on a point the dragon can see within 90 feet. Failure: 7 (2d6) Poison damage, and the target takes a -2 penalty to AC until the end of its next turn. Failure or Success: The dragon can't take this action again until the start of its next turn.
Pounce. The dragon moves up to half its Speed, and it makes one Rend attack.
How to run Adult Green Dragon
A green dragon on the party's side is not an alliance, it's a contract with a buried clause. Adult greens are Lawful Evil, so they keep their word to the letter while engineering the spirit of it to hurt you. The setup that actually works is mutual hatred: the party and the dragon both want the same enemy gone, and the dragon has decided that helping the players is faster than working alone. Negotiate the favour before any fight. Have the dragon name three things it will not do, in writing, in Draconic, and let the party translate.
In combat with the dragon on the party's side, run it cunning rather than greedy. The Poison Breath cone is a 60-foot problem, so the dragon will angle it to catch the largest cluster of enemies and let the party deal with stragglers. Mind Spike on the enemy caster keeps that caster lit up for an hour, which is the dragon telling the party who to chase. If a player tries to give tactical orders, the dragon ignores them and asks pointed questions about whether they understand what is happening.
The exit is a problem. The dragon will leave the moment the contracted goal is achieved, even mid-combat if it judges the rest is mop-up. If the party tries to extend the relationship, the dragon politely accepts the next favour, names a price the party can't pay yet, and leaves a Geas on whichever character agreed verbally. They have just been recruited as a long-term asset.
Write the dragon's contract on an actual index card before session. When the party tries to renegotiate at the table, slide the card across and ask which clause they're invoking.
An adult green dragon is the manipulator of the chromatic family, and the encounter should start before the party knows the dragon exists. With Deception +9 and Persuasion +9, an adult green can run a polite barony for years from inside a hollowed-out forest hill. By the time the players figure out who they've been talking to, half their NPCs are already on a Geas. The fight, when it happens, is the second act, not the first.
When swords are drawn, lead with Poison Breath if it's available. 16d6 poison in a 60-foot cone, DC 18 Con save, average 56 damage on a fail. Even on saves the casters bleed. Then settle into Multiattack for three Rend at +11 (22 average each), or replace one Rend with at-will Mind Spike to stick a damage-over-time tracker on the wizard who keeps Counterspelling you. Mind Spike at level 3 also reveals the target's location for an hour, which matters if anyone tries to teleport away.
Legendary actions are where this dragon teaches a hard lesson about action economy. Noxious Miasma drops a 20-foot poison sphere with DC 17 Con and a -2 AC penalty for a round, which sets up the next Multiattack. Pounce gets you out of a melee pin without provoking, and Mind Invasion stacks another Mind Spike on the priority target. Spend Legendary Resistance (3/Day) on whatever spell would actually end the fight: Banishment, Hold Monster, Polymorph. The dragon is intelligent enough to know which is which.
Greens do not last-stand for honour. Once Bloodied with Poison Breath spent, fly to swim speed in the nearest river and use Amphibious to disappear underwater. Geas any prisoner the party rescued to report back monthly. The reckoning is for next session, not this one.
Stat block from the System Reference Document 5.2.1 © Wizards of the Coast LLC, used under the Creative Commons Attribution 4.0 license.