Draftoku — Rules and Strategy
A daily puzzle that puts card drafting on top of sudoku. You are not solving for which number goes where — you are surviving the hand you were dealt.
What makes it different from sudoku
Ordinary sudoku asks «what belongs in this cell». Draftoku does not let you choose the number. Cards come to your hand from a deck, and the only thing you decide is which cell to put the card you are holding into. So the question changes — not «where does this go» but «can I place this safely right now, or do I have to throw it away».
The sentence that matters
Every move looks legal. About a third of them are traps.
The rules permitting a placement does not make it safe. A move that is legal right now can leave the board in a state where no remaining cell can be filled at all, and the run dies. That is the only way you lose this game.
Core rules
- Board — the daily is 9×9. Digits cannot repeat within a row, a column or a 3×3 box, same as sudoku.
- Hand — cards arrive from the deck. The deck's composition is derived from the solved board, so counting what is left leaks nothing about the answer.
- Placing — put one card from your hand into an empty cell. That is one turn.
- Discarding — a card you cannot use can be thrown away. It costs one ⚡ and does not consume your turn. The discarded card goes back into the deck fourth from the top — it is not gone forever, only deferred.
- ⚡ tokens — your shields for the day. Depending on the weekday you get two or three. At zero ⚡ you have no shield left, and a single unsafe move ends the run.
- CONTINUE — when you have made a fatal move, one ⚡ can undo it. But the moment you do, your grade ceiling for the day drops to B. You are trading your best possible result for staying alive.
- Win / lose — fill the board to win; lose when there is no way left to fill it. On a loss, an autopsy shows which cell died and when.
The weekday dial
Difficulty changes by day of the week, and the number of empty cells moves together with your ⚡ count.
- Mon · Tue · Wed — 30 empties, 2 ⚡. Fewer cells, but fewer shields: unforgiving of misjudgment.
- Sun · Thu · Fri — 34 empties, 3 ⚡. The recovery / mid-difficulty band.
- Saturday — 38 empties, 2 ⚡. The hardest day of the week.
The puzzle for a given date is identical worldwide. It is generated deterministically from the date and never calls Math.random.
Strategy
1. ⚡ is a discard budget, not a stack of lives
Hoarding ⚡ until the end feels correct and usually is not. Spending it early to throw away dead cards keeps the quality of your hand up. Refuse to discard, keep placing marginal cards, and by the midgame all three cards in hand have nowhere legal to go. At that point having ⚡ left does not help — you are already lost.
2. On Mon–Wed, notice the «2 ⚡» dial first
Thirty empties looks easy, but you only have two shields. Start those days planning to discard once. Discard twice and you have no room left to CONTINUE.
3. A discarded card comes back four cards later
Discarding does not delete a card — it inserts it fourth from the top of the deck, so roughly four turns later the same card returns. If you have not opened a home for that digit in the meantime, you will discard it again and burn a second ⚡ for nothing. When discarding, ask: will a cell that accepts this number exist within four turns?
4. Expect traps to detonate late
Puzzles are selected so that the trap surfaces in the back half. Twenty smooth opening turns are not evidence that you are safe. Once the board is more than half full, start counting how many candidates each placement removes from the cells still open.
5. Use CONTINUE only to protect a streak
CONTINUE caps your grade at B. If you were playing for an S or an A, that run has already lost its purpose. A streak changes the math — finishing at B beats losing. Decide by asking what you are trying to protect today.
6. Warm up in arcade
The daily is once per day. There is a 6×6 arcade with three stages (easy / normal / hard) that does not touch your streak or statistics. Test new instincts there. Stage 3 turns the legal-cell hint off.
FAQ
Does turning on the legal-cell hint make it easier?
It makes it less confusing, not safer. The hint shows which cells the rules permit — it says nothing about whether those cells are safe. The traps live in exactly that gap.
Can I deduce the answer from how many cards are left?
No. The remaining deck count is derived from the solved board and is identical no matter which solution you are heading toward — it leaks not one bit of information.
Where is my progress stored?
In your browser only. What is saved is the seed plus the list of moves you made; loading replays them from the start to restore the board.
Does a shared result contain the answer?
No. The function that builds the share card is not even passed the board, the deck, or the starting digits.
Design note — why «legal» and «safe» are separated
Most puzzle games simply forbid moves that break the rules. Draftoku allows every move the rules permit — including the ones that will kill the board twenty turns later.
Blocking them would leave no judgment in the game. Show only the placeable cells and let the player pick any of them, and what remains is clicking, not deciding. The traps have to stay for the question «should I play this card or throw it away» to mean anything.
What we added instead is the autopsy: on a loss it shows which cell died and when. It does not prevent the mistake — it stops you making the same one twice. The legal-cell hint takes the same stance: it reduces confusion but never tells you whether a cell is safe.
Other guides
- Murder Grid — rules and strategy · a daily deduction puzzle where sudoku earns the clues that catch two liars
- Moonlight Exchange — rules and strategy · an investing-education game across 36 months in a fictional city
- About playbuns · design principles, how the games are built, our advertising rules
This page is updated whenever the rules change. If you spot an error, tell us through contact.