AlgoCraft

Learn algorithms in Minecraft. Craft an Algorithm Computer, write real Java right next to your base, and solve 500 built-in problems. Accepted solutions turn into survival loot, daily streak rewards and trophies you can hang on your wall.

Forge 1.20.1 · NeoForge 1.21.1 · 500 problems · English & 简体中文

Current release: 0.1.0 Beta (0.1.0-beta). This early Beta is intended for player feedback on the learning flow and survival reward balance.

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Start in five minutes

1. Craft the Algorithm Computer from 6 iron ingots, 2 redstone dust and 1 glass. The recipe unlocks when you pick up redstone.
2. Place it and right-click. The IDE opens with the problem list on the left, the statement in the middle and your code on the right.
3. Pick an easy problem such as Two Sum, Contains Duplicate or Valid Anagram. Every problem comes with starter code and the method you need to fill in.
4. Run to check the visible examples, then Submit when you are confident.
5. Collect your reward, then come back tomorrow to keep your streak alive.

A little Java helps: you should be comfortable with methods, loops and arrays. Start with the Easy problems and work up.

Two ways to code

In-game IDE. Everything happens at the computer: search problems, read statements and diagrams, edit code with syntax highlighting, and see compiler errors and results in the terminal. Your draft is saved per problem, so you can switch problems and come back later.

Web IDE. Press Web to open a bigger editor in your browser, with the full Monaco editor (the editor from VS Code) and your submission history. It runs on your own computer and submits through your connected player, so the result counts exactly like an in-game submit.

Run compiles your code and checks the examples you can see. Submit is judged by the server against hidden tests too, and only an accepted Submit counts toward progress and rewards.

500 problems, ready from the start

The official bank ships inside the mod and works offline: 172 Easy, 205 Medium and 123 Hard problems covering arrays, strings, hash tables, two pointers, stacks, linked lists, trees, graphs, backtracking, greedy algorithms and dynamic programming. Statements are written for first-time readers, with grids, trees, graphs and linked lists drawn as diagrams where words are not enough. Problems and the IDE are available in English and Simplified Chinese.

Rewards that fit your survival world

With rewards enabled, your first accepted clear of a problem gives items and XP. Harder problems give more, and so does your progress: AlgoCraft looks at your gear and scales the loot for early game, diamond gear and netherite gear. For example, a first Hard clear gives 5 diamonds, 3 golden apples and 4 iron blocks early on; with netherite gear it gives a netherite ingot, 2 enchanted golden apples and a nether star.

Days are counted on the server's clock; miss a day and the streak starts again from 1. Each rewarded solve also has a 10% chance of a lucky bonus drop.

A trophy shelf worth building

Achievements become real 3D trophies in five tiers: bronze, silver, gold, diamond and netherite. Each one is engraved with your name, the date and the achievement, and can be placed on a floor, shelf or desk, or displayed in an item frame. Breaking a placed trophy returns it with its engraving intact. There are 23 achievements: solve milestones (1 to 500), streaks (3 to 100 days), difficulty goals, and specials like Night Owl, Speed Demon, Perfectionist and the netherite Completionist for clearing every problem in a bank.

Built for servers

The server owns the problem banks. Everyone on a server sees the same public problems, public submissions are judged on the server, and progress and rewards are stored with the world. Players download the published statements and images automatically when they join.

Only the server console or an operator (permission level 2) can manage public banks. In the in-game IDE, Bank update guide shows the commands below; ordinary players receive server banks automatically and do not see an update control.

Use Import → Official format for a JSON template and format guide. The guide links to the official bank and GitHub source.

Players can still import their own problems for private practice. Personal imports stay on their computer and never give server rewards, so nobody can farm loot with homemade easy problems. Server owners can turn rewards off with enableRewards=false; progress is still saved.

Download

CurseForge · Modrinth · GitHub

Install

Choose the JAR matching your Minecraft version and loader, then put it in mods/. For multiplayer, the server and every player need matching Minecraft, loader and AlgoCraft builds. Both versions have the same 500 official problems, diagrams, progression and rewards.

FAQ

Do I need to know Java? Basic Java helps. Each problem gives you the class and method to complete, and the examples show what to return.

Does it work offline? Yes. The official bank, the in-game IDE and judging all work without internet. Only the Web IDE loads its editor from the internet.

Can players cheat by importing easy problems? No. Rewards and trophies only come from public banks that the server installed.

Can I use it in a classroom or club server? Yes. Install your own bank with /algocraft bank install, and everyone on the server gets the same problems.

Trailer music: “Voxel Revolution” by Kevin MacLeod (incompetech.com), CC BY 4.0. Sound effects by Kenney (CC0).