Danger levels and Nightmare unlock

Each danger level is unlocked by winning a run on the level below it, with any character. Nightmare is the exception: it needs at least 10 wins on Danger 5, each with a different character or on a different zone. Wins you already had before Nightmare was added count.

For the characters and builds that win at these levels, see how to beat Danger 5 and how to beat Nightmare.

What each level adds

Each level keeps the effects of the levels below it. The damage and health percentages are totals for that level.

Level	Enemy damage and health	Other changes
Danger 0	Normal	None
Danger 1	Normal	New enemies appear
Danger 2	Normal	Elites and hordes appear
Danger 3	+12%	Win here to unlock the ban system
Danger 4	+26%	More elites and hordes
Danger 5	+40%	Two bosses at once in wave 20
Nightmare	+60%, and +10% enemy speed	Environmental projectiles, obscuring fog, Nightmare-only enemies

Danger 5 is +40% in total, not +12 +26 +40.

Nightmare events

• Environmental projectiles. On some waves, arrow-shaped bullets cross the map for the whole wave with increasing speed and number. The arrow points along their path. Accessibility options can turn them off or put them on every wave; the run title then shows the change.
• Obscuring fog. One wave in each group darkens the map except around you: wave 5, 6 or 7; 10, 11 or 12; and 16, 17 or 18. Structures and pets also light the area around them, and explosions briefly light the fog. Items with fog visibility: Candle 25%, Campfire 50%, Lantern 75%, Greek Fire 75%, Lighthouse 100%.
• Nightmare enemies. Stronger versions of existing enemies: seven in the Crash Zone (including Horned Fly, Horned Spitter and Mad Slasher) and ten in the Abyss (including Bloated Pufferfish, Brainy Squid and Cool Walrus).

Update 1.2 made Nightmare easier: fewer projectiles from Horned Fly, Bloated Pufferfish and Horned Spitter, slower Scaled Stargazer, Junkie and Dire Junkie, less health for Brainy Squid, Cool Walrus and Horned Bruiser, and smoother Crash Zone waves where spawns used to overlap.

Planning the ten Danger 5 wins

The ten wins can mix characters and zones. With Abyssal Terrors or Primal Dread, one character can count more than once if each win is on a different zone. The Crash Zone, the Abyss and the Jungle give a single character up to three qualifying wins.

The character selection screen shows the highest danger level you have beaten with each character, so you can see which ones still lack a Danger 5 win. With the Random zone option, the screen shows the lowest result across zones.

Rewards

• Wounded. Winning any Nightmare run unlocks the Wounded, who dies in one hit, starts with a Tardigrade, and never sees Max HP, HP Regeneration, Life Steal or Armor items in shops and crates.
• Rail Gun. Winning any run with the Wounded unlocks the Rail Gun, which gains base damage every 5 seconds until you are hit.
• Frames. Each character you beat Nightmare with gets a frame on the character selection screen.