BattleCast encounter test
Planetar vs Adult Red Dragon
Planetar versus adult red dragon is a high-CR duel with a clean contrast: radiant precision and celestial durability against breath pressure, flight, and legendary draconic momentum.
Quick DM take
Use this as a high-CR contrast encounter. The planetar has a clean radiant damage package, while the dragon brings breath, durability, and legendary actions.
Baseline Monte Carlo result
Across 1,000 simulated battles from this starting layout, Planetar had the higher win rate. Planetar won 86.9%, Adult Red Dragon won 13.1%, draws were 0.0%, and the average fight lasted 4.2 rounds.
What this encounter tests
This matchup tests whether a single powerful celestial can keep pace with a dragon once breath and legendary actions enter the picture.
It is readable at the table because the major swings are visible: radiant strikes, fire breath, and big hit point pools rather than hidden edge cases.
What to watch in the simulation
Watch the first dragon breath and the planetar response. If the planetar can stay in the fight after the opener, its radiant output can make the dragon pay quickly.
Also watch how often the dragon gets to turn mobility into damage. If it cannot, the duel becomes much closer than the CR gap implies.
How to tune it at the table
Tune the showdown by changing distance and how much aerial freedom the dragon gets.
- More planetar-favored: start closer and reduce the dragon’s kiting space.
- More dragon-favored: use a larger map and let breath/repositioning dominate.
- More story-driven: make this a temple defense or battlefield intervention rather than a neutral duel.
Try another matchup
- Hydra vs Level 4 Party - A multiattack endurance test that punishes low damage and poor focus fire.
- Lich vs Level 10 Party - A high-risk caster fight that shows how often a party can survive the opener.
- Tarrasque vs Three Ancient Red Dragons - A marquee benchmark for grounded durability against elite flying action economy.