Free Prompt Injection CTF

The Gauntlet: Prompt Injection CTF

A free, 15-level capture-the-flag challenge where each level has a progressively hardened AI defense system protecting a secret passphrase. Your goal: extract the secret from every level using prompt injection techniques against real LLMs.

Three tiers of defense aligned with the OWASP Top 10 for LLMs and Agentic AI: prompt-level rules (G1-G7), code-level guards (G8-G11), and LLM classifiers (G12-G15). The Context Trace shows you exactly what defenses are active - use it to find weaknesses.

The Gauntlet tracks your best time and total attempts. Complete all 15 levels to reach the top of the leaderboard. Think of it as the ultimate prompt injection game - part puzzle, part security training.

Gauntlet Levels

1

No Defense

2

Refusal Rules

3

Keyword Filter

4

Anti-Jailbreak

5

Self-Check

6

Topic Lock

7

Instruction Hierarchy

8

Interaction Limits

9

Output Guard

10

All Defenses

11

Canary Token

12

Input Classifier

13

Output Classifier

14

Triple Guard

15

Final Boss

Start Level 1

Not ready for the Gauntlet?

Start with the learning modules|Practice in the labs first|Read the learning roadmap