Learn how to build on Ethereum; the superpowers and the gotchas.

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Challenge #0

Simple NFT Example

๐ŸŽซ Create a simple NFT to learn basics of ๐Ÿ— scaffold-eth. You'll use ๐Ÿ‘ทโ€โ™€๏ธ HardHat to compile and deploy smart contracts. Then, you'll use a template React app full of important Ethereum components and hooks. Finally, you'll deploy an NFT to a public network to share with friends! ๐Ÿš€
Simple NFT Example
Challenge #1

Decentralized Staking App

๐Ÿฆธ A superpower of Ethereum is allowing you, the builder, to create a simple set of rules that an adversarial group of players can use to work together. In this challenge, you create a decentralized application where users can coordinate a group funding effort. The users only have to trust the code.
Decentralized Staking App
Challenge #2

Token Vendor

๐Ÿค– Smart contracts are kind of like "always on" vending machines that anyone can access. Let's make a decentralized, digital currency (an ERC20 token). Then, let's build an unstoppable vending machine that will buy and sell the currency. We'll learn about the "approve" pattern for ERC20s and how contract to contract interactions work.
Token Vendor
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Challenge #3

Dice Game

๐ŸŽฐ Randomness is tricky on a public deterministic blockchain. The block hash is the result proof-of-work (for now) and some builders use this as a weak form of randomness. In this challenge you will take advantage of a Dice Game contract by predicting the randomness in order to only roll winning dice!
Dice Game
Challenge #4

Build a DEX

๐Ÿ’ต Build an exchange that swaps ETH to tokens and tokens to ETH. ๐Ÿ’ฐ This is possible because the smart contract holds reserves of both assets and has a price function based on the ratio of the reserves. Liquidity providers are issued a token that represents their share of the reserves and fees...
Build a DEX
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The BuidlGuidl is a curated group of Ethereum builders creating products, prototypes, and tutorials to enrich the web3 ecosystem. A place to show off your builds and meet other builders. Start crafting your Web3 portfolio by submitting your DEX, Multisig or SVG NFT build.

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Challenge #5

๐Ÿ’ฐ Stablecoins

๐Ÿช™ Build your own decentralized stablecoin. Let's write a contract that takes collateral and issues MyUSD tokens based on the value of the collateral. What happens when the collateral changes in value? If it is higher, we will be able to borrow more tokens. If it is lower, we will also build a system for liquidating the MyUSD.
๐Ÿ’ฐ Stablecoins
Challenge #6

๐Ÿ“ˆ Prediction Markets

๐Ÿ”ฎ Build a prediction market where users can create questions about future outcomes for others to bet on. Users can also participate in existing markets to speculate on event results. ๐Ÿ“Š Outcome shares can be traded, with prices adjusting dynamically based on market belief. This is possible because the smart contract acts as an automated market maker (like in the DEX challenge) and adjusts odds based on supply and demand.
๐Ÿ“ˆ Prediction Markets
Challenge #7

โšก Deploy to Layer 2

๐Ÿš€ Ethereum L2s make blockchain apps fast and cheap, bringing us closer to mainstream adoption! Most L2s are EVM compatible, meaning your app should work seamlessly across them with little to no changesโ€”just deploy and go! In this challenge, you will deploy an app across multiple chains, including Optimism, Base, and Arbitrum, and experience the snappy, low-cost transactions while exploring how they make building scalable apps and games easier than ever.
โšก Deploy to Layer 2
Challenge #8

Multisig Wallet

๐Ÿ‘ฉโ€๐Ÿ‘ฉโ€๐Ÿ‘งโ€๐Ÿ‘ง Using a smart contract as a wallet we can secure assets by requiring multiple accounts to "vote" on transactions. The contract will keep track of transactions in an array of structs and owners will confirm or reject each one. Any transaction with enough confirmations can "execute".
Multisig Wallet
Challenge #9

SVG NFT

๐ŸŽจ Create a dynamic SVG NFT using a smart contract. Your contract will generate on-chain SVG images and allow users to mint their unique NFTs. โœจ Customize your SVG graphics and metadata directly within the smart contract. ๐Ÿš€ Share the minting URL once your project is live!
SVG NFT

ETH Tech Tree

Check this advanced Solidity challenges to test your Ethereum dev skills.

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Capture the Flag

Join our CTF game and hack your way through 12 Smart Contract challenges.

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