Chapter · Master Ethereum
The DAO hack and the fork
In 2016 a project called The DAO raised a huge pile of ETH through a smart contract. Attackers found a flaw in the code and began draining the funds. The community faced a hard choice: change the ledger to reverse the theft, or leave it as written. Most people backed a change, called a hard fork, that returned the funds. A minority refused, arguing the ledger must never be edited. That group kept the old chain, now known as Ethereum Classic.
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What you get asked
In what year did The DAO hack and the resulting fork happen?
The DAO was drained in mid 2016, and the hard fork that reversed it followed weeks later, splitting the network into two chains.
What caused The DAO funds to be drained?
The DAO's contract had a bug. The code ran as written, and the flaw let an attacker withdraw far more than intended. It was a stark lesson in smart contract risk.
The original chain that refused to reverse the hack lives on today as Ethereum ___.
Ethereum Classic (ETC) is the chain whose supporters believed the ledger should never be edited, even to undo a theft.
What deeper debate did the fork reveal?
The split was about principle. One side valued fixing a clear harm, the other valued a ledger that no group can rewrite. Both views still shape crypto today.
Order the key events of The DAO story
Raise, exploit, debate, fork, split. This sequence is why two related chains exist and why smart contract audits are taken so seriously now.
The rest of this chapter
Learn how Ethereum works as a programmable blockchain, from smart contracts and gas to staking, Layer 2s, and DeFi.