Realms is three worlds in one language. Master real, typed Python across the Academy, put it to work hauling resources in the Frontier, then send your bot into the Arena. No blocks. No drag-and-drop. One rover, one rising skill — and a server that re-simulates every run.
How it works
# Storm Country — wake the braindef decide(robot, world): if robot.battery < 20: return robot.recharge() if robot.look("east") == "hazard": return robot.zap("east") if world.nearest("cell") is None: return robot.wait() return robot.move("east")Monaco + Pyodide · runs in the browser
Live sim — one action per tick
You never drive the rover — you program it. Every move costs battery, levels budget the exact optimal route, and recharge() only works on a charger tile. The server re-simulates every run: what you see is what actually executed, so stars are earned, never displayed.
The three worlds
Realms isn't a single ladder anymore. The campaign teaches Python, the frontier turns it into resources, and the arena turns it into wins — three connected worlds, one rising skill.
01Learn
The climb. 148 missions, eight realms, Rookie to Commander — every idea taught once, then earned.
Linear and gated, teacher-driven or self-paced. From your first robot.move("east") to a whole co-op fleet — the campaign is finite, and it's where the technique is born.
Rank · Engineer
Realm 2 — Outpost Relay
02Harvest
Single-player, endless, procedural. Write a harvester — smarter code hauls more. Fresh seed every run, so you can't memorize the map.
A daily contract drops on a hidden, held-out map and pays by rank. Push from Open Rush to The Maze to The Gauntlet. Every resource banks home to your Base — yield scales with code, not clicks.
Today's contract
Open Rush — Regolith Flats
03Compete
Async PvP. Submit your decide() and the server re-simulates bots head to head. Climb a league — the floor is a bot, never a wall.
Entry by rank, ELO within. A live opponent changes every match, so the only way up is code that senses and decides. Competition is the anti-cheat.
Your league
Silver III
One loop
Skill is the currency that moves between them — and every lap makes the next one sharper.
Learn the technique. A new idea, taught and earned, every mission.
Turn coding well into resources. A smarter harvester out-hauls a dumb one.
Spend skill to compete. Climb the ladder — then come back to code better.
Learn → Harvest → Compete → repeat, sharper.
Learn
Academy
Harvest
Frontier
Compete
Arena
↻ Repeat
The daily loop
The flywheel says "repeat" — this is what makes a kid open Realms tomorrow. A companion to nurture, a 30-minute ring to fill, and a streak that protects you instead of punishing you.
Your companion
Today's goal
~30 min
12day streak · best 21
2 freezesMiss a day? A Streak Freeze spends itself and the streak lives. Over-do it and you bank more freezes. Break it anyway and you keep your best-streak trophy — nothing you built is ever lost.
Spark · effort
Earned on every graded run, any difficulty. Records showing up — fills the ring, drives the streak. Not spendable.
Bolts · farming
Abundant salvage you spend on cosmetics — outfits and paint for your companion, décor for your base.
Cores · rare
Won by consistency, not grinding. Safety and prestige — buys Streak Freezes and premium looks.
A warm home for the 90% who aren't here to win a ladder — and the companion you nurture is the very bot the top 10% take to the Arena. The reward loop is the on-ramp between them.Academy + Frontier mint · your Base displays · Arena spends — connective tissue, not a fourth world.
Inside Academy
The campaign in full — one ladder from Basecamp to Tharsis Command. Ranks are earned at boss-gate missions, and each gate drops new verbs. The API is loot.
R0 · Rookie
First moves · sequences
Your first commands. The rover does exactly — and only — what you type.
15 missions
R1 · Builder
Conditionals & sensing
The ground starts lying. Check before you move: look(), then leap.
21 missions
R2 · Engineer
Loops & functions
Stop repeating yourself. Loops and functions turn ten lines into two.
23 missions
R3 · Champion
Data structures · algorithms · the trials
Structures and algorithms — and the trials that guard the far side of the Rift.
23 missions
R4 · Ranger
The live world · the agent loop
The world stops waiting. Write def decide() and the brain drives, tick by tick.
18 missions
R5 · Pathfinder
Search & planning · BFS under fog
Fog hides the maze. Breadth-first search finds what your eyes can't.
18 missions
R6 · Scientist
Data → rules · generalization
Read the data, write the rule — then survive the overfitting exam on boards you've never seen.
14 missions
R7 · Commander
The co-op fleet · multi-agent coordination
One coder, a whole fleet. Coordination is the final concept.
16 missions
Ranks are earned at boss-gate missions — beat the gate, hear the "Rank Up." And the gates drop new verbs: radar, probe, the squad link. Clear the campaign and the Frontier and Arena open wide.
Fair by design
Five stars per mission — and only the first one is about finishing. Every run is re-simulated on the server, so the score is the truth.
The rover reached the goal. That's the floor, not the ceiling — one star of five.
The taught construct is alive in the submitted code — a real loop, a live branch. Graded on the AST, not the output.
No copy-paste unrolling. Code an engineer would sign. Unlocks at Engineer rank.
The route hit the level's exact energy budget. Every move earned its cost.
No wasted battery, no armor lost. The run you replay for the whole class.
Rookie & Builder cap at ★★★★ — Clean unlocks at Engineer.
Every mission reshuffles on every run — and the server grades your minimum across variants. A pasted move list clears one board and dies on its mirror. Code that senses and decides earns the stars everywhere.
Seeded boards stop you memorizing a layout. The Arena goes further: you can't memorize a live opponent. Every match is a fresh mind on the other side, so the only way up the ladder is code that reads the board and decides. Competition is the anti-cheat — fitting, from a robotics-competition org.
Standard issue
Because they're writing real code, they get real tools — in every world.
AI Coach
A Socratic coach that points at tick 37 and line 12, then asks the question that gets them unstuck. It never just hands over the answer.
Debugger
Step through any run and watch variables change and the console print. A real IDE — because they're writing real Python.
Toolbox
Functions students write become gear they keep. Save a helper once, import it on any mission — and carry it into the Frontier.
For teachers
Your console shows the class the way the server sees it — every attempt re-simulated, every misconception named. Assign the Academy; the Frontier and Arena keep them practicing after the bell.
Mapped to CSTA and AI4K12 · bridges to VEX-style robotics autonomy
Request a pilotAlert — 3 students stuck at the Outpost Relay gate
Three worlds. One language.
The Academy is open, the Frontier never runs dry, and the Arena is warming up. Real Python from line one — really graded, really yours.
+9Bolts
+3Cores