▦ Learn
Understand how crypto systems fail — by making them fail.
0xrange is built on one idea: you remember a vulnerability you exploited far better than one you read about. Here is how the learning works.
→ The method
Four principles behind every lab.
Every vulnerable contract ships with its patched twin. You see the exact lines that fail, run the attack, then watch the same attack revert against the fix. The lesson sticks because you felt both outcomes.
No abstract slides. Each concept — reentrancy, oracle manipulation, access control — is attached to a real objective against a live target whose state you watch change as you exploit it.
You learn offence to build defence. Every lab frames the exploit as a lesson in mitigation: guards, checks-effects-interactions, pull payments, manipulation-resistant feeds.
Start from nervous beginner. Annotated code, progressive hints that never cost points, and a terminal that stays hidden until you want it. Ramp to auditor at your own pace.
▦ Learning paths
Pick a track, or follow them in order.
Each path starts with short theory, then runs puzzles → quizzes → labs in order. No prior Solidity assumed — start with Path 00 if you are brand new.
PATH 00
Wallet & user safety
Start here if you have never read a line of Solidity. How blockchains, wallets and signatures work — and the everyday traps that cost real people real money.
- Complete beginner
- 5 steps
PATH 01
Smart-contract security
The core auditor toolkit: state ordering, access control, arithmetic, unchecked calls and delegatecall — each learned by breaking a contract, then reading its fix.
- Beginner → Advanced
- 11 steps
PATH 02
DeFi & oracle security
How lending markets, AMMs and price feeds fail: manipulable spot prices, flash-loaned capital, transaction ordering and predictable randomness.
- Intermediate → Expert
- 7 steps
PATH 03
Bridge & cross-chain security
Bridges hold enormous pooled value behind a trust model. Learn what a signature actually commits to, how thresholds fail, and why verifying the verifier matters.
- Advanced → Expert
- 6 steps