Time, killstreak and no-hit doors
Time doors
Time doors appear in transition levels (levels that are in-between two biomes) and require the player to reach them before the timer has reached a specific benchmark, varying depending on which transition level the door is in. If a time door is not reached and opened within a set amount of time in a run, it will be locked and can't be opened, displayed by the door being chained & red in colour, with the Beheaded trying to kick down the door upon interacting with it. (If the default timer is enabled in the settings, then the time spent in the beginning area of The Prisoners' Cell, transition areas, shops, treasure rooms and lore rooms will not count towards time doors.)
Every time door will contain money (in form of gems and jewels), 20 cells, as well as a 3-choice item altar that consists of either 3 items or 2 items & 1 amulet. Some timed doors also contain a blueprint.
The items on the altars will have a minimum gear quality, depending on how many BSC are active:
- 0-1 BC: +
- 2-3 BC: ++
- 4-5 BC: S
Times for each transition level
| Transition level | Time | Blueprint |
|---|---|---|
| Promenade of the Condemned | 2 minutes |  Assault Shield
|
| Toxic Sewers | 2 minutes |  Frenzy
|
| Dilapidated ArboretumTBS, Castle's OutskirtsRtC | 2 minutes | |
| Ramparts (from PotC/TS/DATBS) | 8 minutes | |
| Ossuary (from PotC/DATBS) | 8 minutes |  Marksman's Bow
|
| Dracula's CastleRtC (from Castle's OutskirtsRtC) | 8 minutes | |
| Stilt Village, Slumbering Sanctuary, Fractured ShrinesFF (from Black Bridge) | 15 minutes |  Root Grenade
|
| Stilt Village, Fractured ShrinesFF, Graveyard (from The NestTBS) | 15 minutes | |
| Graveyard (from Insufferable Crypt) | 19 minutes, 30 seconds | |
| Forgotten Sepulcher | 26 minutes |
Killstreak doors
Killstreak doors (also known as perfect doors) appear in most transition levels.
The contents of the killstreak doors are the same as those of time doors.
Killing an enemy (that can reduce the curse counter) will increase the player's killstreak by 1. The killstreak will be reset when taking any damage. Killstreak doors will still be unlocked if the player's killstreak is reset after achieving the required amount. (Using 
Face Flask or 
Vampirism will not reset the killstreak.)
The required killstreak varies, but for the most part a killstreak of 60 is needed. Some exceptions are Prisoners' Quarters, where a 30 killstreak is required, and the biomes Prison Depths, Corrupted Prison, Infested ShipwreckTQatS, and Dracula's CastleRtC, where no killstreak door is available.
No-hit doors
No-hit doors appear in transition levels after every boss. Similar to time & killstreak doors, they contain money & cells. But instead of a 3-choice altar, a single altar with only a Legendary Item will be present. The Legendary Item will be randomly picked from the pool of unlocked items.
In order to enter no-hit doors, the previous boss stage must be cleared without taking damage throughout, requiring that the boss of that area be defeated flawlessly. Using items like Face Flask that deal damage but do not reset killstreak will still allow access to the no-hit door if the player hasn't received damage from other outside sources, but will sometimes prevent the player from obtaining the flawless outfit/achievement.
Notes
- You can enable the killstreak HUD by going into your Settings, clicking on "Video", scrolling down and ticking the “Display the number of enemies killed without being hit” option.