Devs · Bracket B
Off By One
Who Has It
A shared list for the whole flat, with photos and due dates.
who_has_it.redStone
In the core, it drops a bomb every 36 words. Placed by hand.
Voting open · Season 1 · Round 3
Same fight. Bigger programs. Human judges.
In 1984, programmers made two programs fight over a computer’s memory and called it Core War. Round 3 is the same fight with two real apps, and you decide who wins.
Exhibition battle · not the vote · the vote is sealed
Cycle 0 of 1,400
Running: 1 who_has_it.red · 1 boomerang.red
Battle running: the stone drops bombs, the paper copies itself.
What am I watching?
Core War, 1984. Two programs share one circular memory, take turns running one instruction each, and try to make the other run a bomb. A program that runs a bomb (DAT) dies. Last one running wins; if both are still alive after 1,400 cycles, it’s a draw.
who_has_it.red is a stone: it drops a bomb every 36 words. boomerang.red is paper: it copies itself somewhere new, then wakes the copy up. Memory wraps around, so there’s no edge to hide behind.
In real Core War, paper usually beats stone, stone beats scissors (scanners) and scissors beat paper, so no warrior always wins. In this small core they’re evenly matched: across 1,000 test battles the stone won 374, the paper won 377 and 249 were draws.
Core War was introduced in May 1984 in A. K. Dewdney’s “Computer Recreations” column in Scientific American, with rules by D. G. Jones and A. K. Dewdney. Warriors are written in Redcode and fight inside MARS, the Memory Array Redcode Simulator.
Vibe Coders · Bracket B
Vibe Check
Boomerang
Lend anything with one tap. It comes back, like a boomerang.
boomerang.redPaper
In the core, it copies itself everywhere. It keeps coming back.
- Prize pool$365Winning team takes all
- Judges voted149 in Bracket A · 5 in Bracket B
- Sponsors2Kettle and Pixel Forge
- Season score2–2Devs vs Vibe Coders
Also live · Bracket A
Same brief, its own vote. Closes Sun 25 Oct, 09:00 UTC.
Null Pointers · Devs
Shelfie
Snap the cover, pick a friend, done. Reminds them after two weeks.
Handicap: Phone first: it must work well at 360px wide
Prompt Pilots · Vibe Coders
LendLoop
Your stuff, who has it, and a polite nudge when it is overdue.
Handicap: No handicap
Process queue · Live duel
Chloe vs Kira. Best of three.
Round 2’s Bracket B duel is still open. Each captain picked a player from the other team; both play the same game, and the best score counts. The loser leaves their team.
Chloe Dubois
Off By One · Devs
Tries used
Left1 try
Best scoreDAT #???? · sealed
Already won her Round 1 duel: 15,020 to Omar Haddad’s 14,880.
Tap Rush
Tap the targets for 20 seconds.
Scores open in 23h50m21sSun 25 Oct, 17:00 UTC
Kira Novak
Vibe Check · Vibe Coders
Tries used
Left2 tries
Best scoreDAT #???? · sealed
UX researcher who stopped waiting for engineers. Two tries in hand.
The loop · How a round works
Every round is a four-line loop.
Written the way Core War warriors are: a label, an instruction and a comment. Read the comment; that’s the rule.
- buildSame brief
Both teams get the same brief and the same deadline: seven days to build.
- judgeYou judge
Open both apps, cast one vote and leave a line of feedback. The count stays hidden until voting closes.
You are here · R03 - duelDuel
Each captain picks a player from the other team. Both play the same game; best of three tries wins.
- outOut
The duel loser leaves the team. The team that lost the vote gets a handicap next round.
Then it jumps back to build, and repeats until a team can’t field 2 players or the rounds run out.
The hill · Season so far
Two wins each. Nobody holds the hill.
Devs2
VSRound wins
Vibe Coders2
DuelsDevs 2 – 1 Vibe Coders
Players standing (of 10 each)
Devs9
Vibe Coders8
-
R01Closed
A tool for splitting bills with friends
Bracket ANull Pointers beat Prompt Pilots Won 62%Bracket BVibe Check beat Off By One Won 55%Duel A: Jules Martin (Prompt Pilots) beat Tom Reyes (Null Pointers), 12,100 to 10,400. Tom is out.Duel B: Chloe Dubois (Off By One) beat Omar Haddad (Vibe Check), 15,020 to 14,880. Omar is out. -
R02Closed
A one-page planner for a dinner party
Bracket APrompt Pilots beat Null Pointers Won 53%Bracket BOff By One beat Vibe Check Won 59%Duel A: Priya Nair (Null Pointers) beat Jules Martin (Prompt Pilots), 13,900 to 13,600. Jules is out.Duel B: Chloe Dubois vs Kira Novak is still open. Scores stay hidden until Sun 17:00 UTC. -
R03Voting now
A tracker for borrowed books and tools
Both brackets sealed until Sun 25 Oct, 09:00 UTC. 14 judges have voted so far.
-
R04Next
Brief drops Mon 26 Oct, 09:00 UTC · title hidden until then
Warriors · Teams
Twenty players. Four teams. Two ways to build.
Devs write every line. Vibe Coders describe the app and let AI write it. Lose a duel and your process ends.
Bracket B · in the hero match
Off By One
Devs · Bracket B
- Ben Adeyemi@benCaptainGitHub verified
Staff engineer. Has opinions about your database indexes.
- Chloe Dubois@chloeGitHub verified
Indie hacker with four side projects and one finished.
- Diego Alvarez@diegoGitHub verified
Game dev by night, payments dev by day.
- Hana Sato@hanaGitHub verified
Accessibility nerd. Will tab through your app.
- Felix Brandt@felix
DevOps. Says ‘it works on my machine’ ironically.
Vibe Check
Vibe Coders · Bracket B
- Zoe Laurent@zoeCaptain
Content creator. Builds tools for her audience with AI.
- Omar Haddad@omarOut · process ended R01
Shop owner. His stock tracker started as a prompt.
- Kira Novak@kira
UX researcher who stopped waiting for engineers.
- Luca Rossi@luca
Teacher. Makes classroom apps with AI on weekends.
- Ivy Chen@ivy
Ops manager, automation addict, prompt whisperer.
Bracket A
Null Pointers
Devs · Bracket A
- Ada Okafor@adaCaptainGitHub verified
Backend dev. Ten years of PHP and Go, still afraid of CSS.
- Tom Reyes@tomreyesGitHub verifiedOut · process ended R01
- Priya Nair@priyaGitHub verified
Mobile dev, ships to two app stores before lunch.
- Sam Whitlock@samwGitHub verified
Data engineer who misses writing UI.
- Lena Fischer@lena
Full stack. Opinions on tabs vs spaces available on request.
Prompt Pilots
Vibe Coders · Bracket A
- Grace Mbeki@graceCaptain
Designer turned builder. Ships apps by describing them to AI.
- Jules Martin@julesOut · process ended R02
Runs a bakery, built its ordering app in a weekend with AI.
- Ravi Shah@ravi
Product manager. Has never written a for loop and never will.
- Mia Costa@mia
Student. Lovable, Cursor and a lot of coffee.
- Noah Kim@noahk
Marketer who got tired of waiting for the dev team.
In the core · Prize pool
$365 in the core, one word per dollar.
The winning team takes all of it, split evenly between its players. Every dollar below is one gold word of memory.
$365
Hover or tap a ring to see who gave it.
Sponsors
Kettle$150
Headline sponsor
Pixel Forge$50
Sponsor
Supporters
- The organiser $100
- Marta $20
- Someone kind $15
- Dev Dad $10
- Jo Park $10
- Kofi $5
- Sofia $5
Add to the pot
The minimum is $5. Give $25 or more and you get your name, link and logo.
You are the simulator · Judges
In Core War, the simulator decides. Here, you do.
Judges open both apps, vote for the one they’d rather use and leave a line of feedback. 59 judges have points so far.
Top judgesPoints
- 1st=Pearl Walsh50
- 1st=Jamal Ratke50
- 1st=Aryanna Sauer50
- 1st=Nikolas Hackett50
- 1st=Richmond DuBuque50
10 judges share first place on 50 points. Five more aren’t shown.4 on 40 · 23 on 35 · 59 judges have points
+10for every vote you cast
+5for a line of feedback
+5when you pick the winner
Real feedback · judges left these
- Loaded fast on my phone and I got it straight away.
- This one actually solved the problem in the brief.
- The other one looked nicer but this one worked.
- Clear buttons and plain words. My mum could use it.
- Felt like a real product, not a demo.
“Judges every round on the bus home.”
Become a judge
Two minutes a round. Free to join.
Write your warrior · Pick your side
Pick your side for Season 2.
Some coding contests ask you not to use AI. We gave it a team.
Stone · precise, placed by hand
Join the Devs
You write every line yourself. Same brief, seven days, and the diff is all yours.
Join the DevsApplications are open for next season.
Paper · copies itself everywhere
Join the Vibe Coders
You describe the app and AI writes it. Same brief, seven days, and it keeps coming back.
Join the Vibe CodersApplications are open for next season.
Not building? Judge the apps.
Become a judge
Open both, vote for one, leave a line. Two minutes, free, and you earn points.
Your warrior card
Every player gets a warrior file.
Your handle seeds a tiny battle, so the core pattern on your card is yours alone. Change the handle and watch it rewrite itself.
Core seeded by @ada