The Root Hollow · boss guide · floor 20 and every fifth floor after it
How to beat The Mournroot
Every attack is drawn on the floor first. The shortest wind-up is 0.75 s; the longest dodge from a standing start is 0.19 s. Watch the ground, not him.
The Mournroot: 4830 HP on floor 20. His codex page.
His rhythm
He steps out 1.5 s into floor 20 and draws his first attack 1.67 s later. Each attack sits on the ground for its whole wind-up while he stands still, lands, and then he rests 1.6 s before the next one (1 s below half HP). Below half HP he gets faster, and some shapes grow: the numbers for that phase are given with each attack. The rest after a landing is your window to hit him.
The waves do not stop while he lives. On floor 20 they are 19% cleavecaps, 17% delvers, 13% husks and 13% skitters and a few others, so clear a lane before you commit to him.
Root plunge
What you see: 3 lines of root spikes, each 9 tiles long and 0.9 wide, 24° apart, from him toward you, and to either side, drawn on the ground for its whole wind-up of 1 s, 0.75 s below half HP. Damage: 74 on floor 20, 120 on floor 25 and 193 on floor 30 (26 before the floor’s multiplier). How often: Every attack while he is above half HP; below it, 40% of his attacks when you are within 4 tiles of him and 65% when you are further off.
How to dodge: The middle line runs from him through where you stood, so step sideways off it: clearing its 0.9-tile width plus your body takes 0.19 s. Then stop. The side lines open 24° either side of it, so 4 tiles from him the next line is only 1.8 tiles over, and a long sideways run walks into it. Further out the gaps between the lines widen; close to him they narrow to nothing.
Spore bloom
What you see: 3 rings round his own spot, 0.9–2.1, 3.5–4.7 and 6.1–7.3 tiles from his centre, with 1.4-tile gaps between them, drawn on the ground for its whole wind-up of 0.9 s. Damage: 51 on floor 20, 83 on floor 25 and 134 on floor 30 (18 before the floor’s multiplier). How often: Only below half HP; then 60% of his attacks when you are within 4 tiles of him, 35% when you are further off.
How to dodge: Every ring is drawn the moment he raises his arms, and they burst from the inside out, ring 1 after 0.9 s, ring 2 after 1.15 s and ring 3 after 1.4 s. Standing in a gap (2.1–3.5 and 4.7–6.1 tiles from his centre) or beyond 7.3 tiles is safe from all of them; your body is 0.68 tiles across, so a gap of 1.4 leaves 0.72 tiles to stand in. Only below half HP does he use it.
What helps
- Anvil Drop: an attack that lands during the 0.3 s the Warrior is in the air misses him. It fires on its own at packs; switch skills to Tap to fire in Settings to time it.
- Move speed shortens every dodge time above: the Warrior walks 4.2 tiles a second before Light Step and gear.
- You have 120 life before gear; on floor 20 his heaviest hit is 74, so 1 mistakes is what a bare Warrior can afford.
The reward
Always two rare items and three magic items, each rolled with magic and rare odds ×2.1 so any of them can come out better, 10 coins of 82 on floor 20, a 50% chance of a unique and a 13% chance of a set piece. When he falls, a waypoint rises in his arena. Touch it and two things happen: floor 20 is unlocked for good as a place the town's stairs can start a new dive, and this floor's portal offers Return as well as Descend, so you can bank everything you carry. Walk to the portal without touching it and it offers Descend only.