SCP: Secret Laboratory is a free multiplayer horror game set inside a Foundation site during a full containment breach. Each round assigns your role at random: Class-D trying to escape, a Scientist waiting on rescue, a Facility Guard, or one of the anomalies hunting everybody else. Death is permanent for that round, and the facility runs on hard timers that will kill you whether or not anything else does.
Boss fights are where SCP: Secret Laboratory tests everything you've learned. This guide covers strategies for bosses across all areas, organized by progression order. For general combat techniques, see our combat guide.
Boss Difficulty Overview
| Area | Difficulty | Recommended Build | Key Equipment |
|---|---|---|---|
| Light Containment Zone | Easy | Scientist | FSP-9 |
| Heavy Containment Zone | Moderate | Scientist | FSP-9 |
| Entrance Zone | Hard | Class-D Personnel | COM-15 |
| Surface Zone | Very Hard | Class-D Personnel | COM-15 |
| Pocket Dimension | Extreme | Class-D Personnel | COM-15 |
Light Containment Zone Bosses
Area difficulty: Easy Recommended level: First 11 minutes 45 seconds of the round Recommended build: Scientist with FSP-9
Strategy
The first bosses teach core combat mechanics. Focus on learning patterns rather than dealing damage. You spawn as Class-D, a Scientist, a Facility Guard or an SCP with no say in the matter. This is your primary tool here.
Key tips:
- Don't rush. Learn the attack patterns first.
- Use Role assignment and respawn waves to create safe windows.
- FSP-9 is enough to handle everything here.
Heavy Containment Zone Bosses
Area difficulty: Moderate Recommended level: Mid round, after decontamination begins Recommended build: Scientist with FSP-9
Strategy
Early game bosses test your understanding of Keycard access levels. Players who skipped learning this mechanic will hit a wall here.
Key tips:
- Keycard access levels is critical for these fights.
- Farm FSP-9 upgrades if you're struggling.
- Consider switching to Scientist if your current setup isn't working.
Entrance Zone Bosses
Area difficulty: Hard Recommended level: Mid to late round Recommended build: Class-D Personnel with COM-15
Strategy
Mid-game bosses are the major skill check. They combine multiple mechanics and punish players who rely on a single strategy.
Key tips:
- You need both Role assignment and respawn waves and SCP-914 refinement mastery.
- COM-15 makes a significant difference. Get it before attempting these.
- See our combat guide for advanced techniques.
Surface Zone Bosses
Area difficulty: Very Hard Recommended level: Late round Recommended build: Class-D Personnel with COM-15
Strategy
Late-game bosses are serious challenges. Build optimization matters as much as mechanical skill.
Key tips:
- Make sure your build is fully optimized.
- COM-15 at max upgrade is recommended.
- Study each boss's attack patterns. Most have 2-3 phases.
Pocket Dimension Bosses
Area difficulty: Extreme Recommended level: Any time SCP-106 is loose Recommended build: Class-D Personnel with COM-15
Strategy
Endgame bosses are the ultimate test. They require mastery of all combat systems and an optimized build.
Key tips:
- Top-tier build with best-in-slot gear is mandatory.
- Master every mechanic. See our combat guide.
- These fights reward patience and pattern recognition above all else.
General Boss Tips
- Learn before you fight: Spend your first attempt observing attack patterns. Don't try to win on attempt one.
- Match your build: Some bosses favor certain builds over others. Don't be afraid to switch.
- Upgrade your equipment: A max-upgraded COM-15 trivializes fights that seem impossible with weaker gear.
- Use Role assignment and respawn waves: The core combat mechanic is your best defensive tool in every boss fight.
- Check the walkthrough: Our walkthrough tells you when you're ready for each boss.
More SCP: Secret Laboratory Guides
- SCP: Secret Laboratory SCP: Secret Laboratory Overview
- SCP: Secret Laboratory Best Builds
- SCP: Secret Laboratory Tier List
- SCP: Secret Laboratory Walkthrough
- SCP: Secret Laboratory Beginner's Guide
- SCP: Secret Laboratory Tips & Tricks
- SCP: Secret Laboratory Weapons Guide
- SCP: Secret Laboratory Combat Guide
- SCP: Secret Laboratory Maps & Locations
- SCP: Secret Laboratory Crafting Guide
- SCP: Secret Laboratory Classes & Characters
Similar Games
If you enjoy SCP: Secret Laboratory, check out these related guides:
- Phasmophobia Boss Guide: horror game with similar mechanics
- Lethal Company Boss Guide: horror game with similar mechanics
- Dead by Daylight Boss Guide: horror game with similar mechanics
