Hard Mode at a glance
| Where | Research Outpost basement, lever near the monitors |
| Door | Steel door on the left side of the main floor |
| Timing | Outpost open from Day 1; Hard Mode starts around Day 3 (Beebom, All Things How) |
| Group play | Each player pulls their own lever; All Things How says it starts once every lever is flipped |
| Can you undo it | No, it is a one-way switch for that run (All Things How) |
| Rewards | Double diamonds at Day 50 and Day 99 (both guides) |
| Sources dated | Jan 25 and Jan 27, 2026 |
The four Hard Mode debuffs
| Debuff | What it does |
|---|---|
| Hungry Deer | Named in both guides; neither explains the exact change, so we do not guess |
| Passive Heals | Named in both guides; All Things How calls it Passive Healing. Exact effect not confirmed |
| Cultist Waves | Named in both guides; exact effect not confirmed |
| Food Rot Spores | The last debuff: makes food inedible, so you eventually starve if you cannot eat (Beebom) |
Step by step
- Walk to the Research Outpost, the large white building north of the main campfire area.
- Open the steel door on the left side of the main floor and take the stairs down to the basement.
- Pull the lever by the monitors. In a group, every player pulls their own.
- A cutscene plays and Hard Mode begins. Rifts open on the map and corruption starts to spread.
What corruption does
Corruption is a percentage that rises the longer you survive. The outpost monitor shows the corruption level, the active debuffs and the rift count (All Things How).
To keep it down, chop the corrupted trees and kill the corrupted animals near each rift until the corruption is gone. Both guides say new rifts appear as nights pass; All Things How says roughly every night.
All Things How says a run can have three debuffs active at once.
Rewards
Once Hard Mode starts, the outpost chests can give a Research Monitor Blueprint, Bandages, an MRE and a Medkit (Beebom). All Things How lists the same items for the basement chest.
Both guides say Day 50 and Day 99 pay double diamonds. Neither describes a separate Night 99 event.
What we could not confirm
Other guides disagree on the deadline. Some say you must pull the lever before the second night, others say any time before Hard Mode begins on Day 3. We could not open those pages to check, so pull it on Day 1 or 2 to be safe.
We also could not verify claims that meteors, frogs or UFOs block Hard Mode, or that the campfire must be upgraded first. Treat those as rumours. Guides are from late 2025 to early 2026 and the game updates often, so check numbers in game.
Tips
- Pull the lever on Day 1 or 2. The two guides we read allow Day 1 but disagree on how late you can go.
- Agree as a group before anyone pulls a lever, because it cannot be switched off.
- Clear each new rift as soon as it appears so the corruption level does not run away.
- Open the outpost chests once Hard Mode starts.
- Bring a strong class and plenty of food in case Food Rot Spores turns up.
FAQ
Where is the Hard Mode lever in 99 Nights in the Forest?
In the basement of the Research Outpost, a large white building north of your camp. Use the steel door on the left of the main floor.
Can you turn Hard Mode off?
All Things How says no: once it is active it stays on for that run.
What do you get for Hard Mode?
Double diamonds at Day 50 and Day 99, plus chest loot from the outpost such as Bandages, an MRE and a Medkit.
Does everyone in the group have to pull the lever?
Both guides say each player pulls their own lever, and All Things How says it starts once all of them are flipped.
More 99 Nights in the Forest pages
- 99 Nights in the Forest Cultist
- How to Get Bandages in 99 Nights in the Forest
- How to Get Diamonds in 99 Nights in the Forest
- Best Classes in 99 Nights in the Forest
- 99 Nights in the Forest codes
- 99 Nights in the Forest badges
- 99 Nights in the Forest wiki: live stats
Sources
Checked Nov 13, 2026. Community wikis are edited by players, so numbers marked “per” one wiki may change after an update.