Sweep League
Every board can be solved by pure logic. How cleanly can you do it?
How the league measures you
- 3BV is the clicks the board needs without chording, after the free opening.
- Efficiency is 3BV ÷ your clicks; a chord can push it past 1.
- Time appears only after you finish, as 3BV per second. No clock ticks at you.
- Help (the Coach Lens, Ask why) is always there, and your token says when you used it.
How are you feeling?
Cast, stories & more
Why is Minesweeper famous in computer science?
In 2000 the mathematician Richard Kaye proved that deciding whether a Minesweeper position is consistent — whether any arrangement of mines fits all the numbers — is NP-complete. That puts it in the same family as some of the hardest puzzles computers know: nobody has found a fast method that works for every possible board, and finding one would answer a million-dollar open question (P vs NP).
A board that computes
Tap the input square. The end of the wire copies it; the end of the NOT gate is the opposite.
😄 Brain break
Meet the cast — the characters who teach this
-
Surefoot only steps where she is SURE; asks which square the numbers prove -
Bevvy A bee who knows the fewest clicks a board could take - its 3BV -
Clicksy A cricket who counts every wasted click - efficiency is 3BV divided by clicks -
Oddsley An owl who weighs every arrangement the numbers allow - the exact odds of a mine -
Chordy A crab who opens a whole ring of squares at once when a number's mines are all flagged -
Floody A duck who knows a zero opens its whole empty region in one go -
Knowsley A red panda who knows every board can be solved by knowing, never by guessing -
Rewinda A squirrel who checks a run by re-playing every move, never by trusting it -
Samesby A penguin who knows a race code gives both racers exactly the same board -
Sumsy A hamster who knows the total number of mines shapes the odds of every hidden square -
Tickwell A hare who knows your speed is shown only AFTER you finish, never while you play
Ensemble stories — the cast together
What next? Pick a door
- More like this TableForge Is your board game fair? VerdictForge Who has to prove it? CountCraft Can you count it two ways?
- A bit harder CornerstoneQuest Which corner makes the best first cottage? IsleForge What will you trade for what you need? HuntForge Can your family solve your hunt?
- Something different ThreadForge Which causes tangled together here? BeatForge Can you build the beat you hear? SortTales Which sort is fastest for this list?
Where this game comes from
Mine-clearing number puzzles
Grid games where numbers tell you how many hidden mines are next door appeared on home computers in the early 1980s. The best-known version was made by Curt Johnson, and ported to Windows by Robert Donner; it came out in a Microsoft Entertainment Pack in 1990 and then with Windows 3.1 in 1992. In that classic game some boards force a guess, often a coin toss between two squares.
One thing to hold: Each number is a promise about the eight squares around it, and nothing else.
Why it matters: In 2000 the mathematician Richard Kaye proved that deciding whether a board’s numbers can all be true is among the hardest problems in a famous class called NP (it is “NP-complete”). A quick way to check any board would answer one of the biggest open questions in mathematics.
What we don’t know: Who wrote the very first one is still argued about; several early games had the same idea.
Dates:
- 1990 Curt Johnson and Robert Donner’s game ships in a Microsoft Entertainment Pack.
- 1992 It comes with Windows 3.1.
- 2000 Richard Kaye proves the board-checking problem is NP-complete.