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Star Battle: Where the Puzzle Came From

Dutch puzzle maker Hans Eendebak made Star Battle for the 2003 World Puzzle Championship. How it became Two Not Touch and LinkedIn's Queens.

By , maker of Puzzle Picnic · · 9 min read

Star Battle was invented by Hans Eendebak, a Dutch puzzle maker, for the 12th World Puzzle Championship, held at the Papendal sports centre near Arnhem in the Netherlands in 2003. The first Star Battle asked for two stars in every row, column and region, with no two stars touching. From the championship it spread to puzzle magazines and websites, then to the New York Times as Two Not Touch in 2020 and to LinkedIn as Queens in 2024.

This post is for anyone curious about the puzzle's story. It sticks to what the record shows: the World Puzzle Federation's own newsletters, the publishers and the people who made the puzzles. Where a detail is not documented, it says so. If you want to learn to solve rather than read history, start with how to play Star Battle.

Invented for the 2003 World Puzzle Championship

Star Battle was created for the World Puzzle Championship of 2003, the twelfth edition of the yearly contest. The first championship was held in New York in 1992, according to Wikipedia's history of the event. In 2003 the host was the Netherlands.

The World Puzzle Federation's newsletter number 9, published in 2004, gives the details. The decision to give the 2003 event to the Netherlands was taken at the 2001 championship in Brno. The hosts were Rob Geensen and his staff from Puzzelsport. The core organising team was Geensen, Hans Eendebak and Jan Lam, working with the agency that had also helped them run the 1996 championship in Utrecht. They chose Papendal, "the national sportscenter and home of the Dutch Olympic movement", as the venue. The Federation's general assembly met in Arnhem on 16 and 17 October 2003.

Geensen and Lam wrote that they wanted "a fair language- and culture-neutral competition", and Eendebak and Tim Peeters, introducing a selection of the championship's puzzles, described two years of "trying different formats and innovating and testing new puzzles". Star Battle fits that brief well. Its rules need no words and no numbers beyond a star count, so a solver from any country starts on equal terms.

Ulrich Voigt of Germany won the individual title that year, ahead of Wei-Hwa Huang and Roger Barkan of the USA, and Germany topped the team table, according to the same newsletter.

The first rules: two stars in every row, column and region

The first Star Battle was a two-star puzzle. The 2004 newsletter reprints a selection of puzzles from the championship, chosen by Hans Eendebak and Tim Peeters, and among them is "Star Battle, Hans Eendebak" with this instruction:

Apart from the number of stars, those are the rules still used today. Two stars on a 10x10 grid is the classic size on puzzle sites such as KrazyDad. One-star versions on smaller grids are the gentler entry point, and they are what LinkedIn's Queens and Puzzle Picnic's Stars use.

VersionStars per row, column and regionTypical grid
The 2003 original2Competition grid (size not given in the newsletter text)
Classic two-star210x10
Three-star314x14
One-star15x5 to 9x9

The typical sizes come from the formats KrazyDad offers (1-Star 8x8, 2-Star 10x10 and 3-Star 14x14) and from Puzzle Picnic's own one-star grids, which run from 6x6 on Easy to 9x9 on Expert.

Hans Eendebak, the puzzle's inventor

Hans Eendebak was a Dutch puzzle maker and organiser who did a great deal to build puzzle solving as a sport in the Netherlands. The fullest account of his life is the obituary in the World Puzzle Federation's newsletter number 24 (2019), written by René Gilhuijs, chairman of the Dutch puzzle association WCPN. It says:

  • He was a member of the Dutch team at a few of the first world championships, but "his strength lay in puzzle making and organization".
  • He created "quite a few puzzles that nowadays are considered classics", Star Battle among them.
  • He co-organised both world championships held in the Netherlands, in 1996 and 2003, and as captain of the Dutch team he took part in almost every championship since.
  • He served for a few years on the board of the World Puzzle Federation.
  • He first promoted puzzle sport from his job at one of the big Dutch publishers of puzzle booklets. When that publisher ended its involvement in puzzles as a sport in 2013, he founded his own association, WCPN (World Class Puzzles from the Netherlands), which runs the yearly Dutch Puzzle and Sudoku Championships.

Hans Eendebak died on 12 January 2019, aged 52. Star Battle, a puzzle he wrote for one championship, now reaches newspaper readers and app players who have mostly never heard his name.

Cattle: the puzzle before Star Battle

Star Battle had a Dutch ancestor called Cattle, by Tim Peeters. Grandmaster Puzzles' rules page for Star Battle explains the link: Cattle already had regions and the rule that objects may not touch, but instead of a fixed number per row and column it gave counts outside the grid for each row and column, the way Battleship puzzles do. The World Puzzle Championship wiki dates Cattle to 1999.

That makes the step from Cattle to Star Battle easy to see. Replace the outside counts with "the same number in every row and every column", and the clues disappear entirely: the grid's regions are the whole puzzle. Grandmaster Puzzles describes the idea as "likely" arising from Cattle, so treat the family tree as well-founded rather than proven.

The resemblance to Battleships runs deeper than the counts. Battleship solitaire also forbids its ships from touching, even at a corner. If you play both, the habit of marking all eight squares around an object carries straight over; our post on why ships never touch shows it from the Battleships side. Where the name "Star Battle" itself came from is not documented in any source this post could check, so we do not guess.

How a championship puzzle spread

Star Battle spread first through the world of competitive puzzling, which has a built-in way of sharing new genres. The 2004 newsletter explains that members of the World Puzzle Federation "are entitled to publish WPC puzzles for free in their own magazines", and that as a result "all over the world more WPC-like puzzles are being offered to the general puzzle audience". A new genre that worked well at a championship could appear in national puzzle magazines soon afterwards.

Star Battle also kept coming back to the championships themselves. The World Puzzle Championship wiki lists Star Battle puzzles at more than a dozen championships between 2010 and 2024, often as new variants: toroidal grids that wrap around at the edges, an anti-knight rule, coloured stars with their own touching rules, and hybrids such as Comet, which combines Star Battle with a loop puzzle and first appeared at the 24-Hour Puzzle Championship in 2007.

Puzzle websites carried it to everyone else. KrazyDad, the site of the puzzle maker Jim Bumgardner, published the puzzle under the name Star Battle "for several years" before 2020, by his own account, in one-, two- and three-star versions. Grandmaster Puzzles has published many Star Battles too. Simple rules also suit computers: a program can generate a grid and check that it has exactly one solution. That is how Puzzle Picnic makes its Stars puzzles, with a solver confirming that every grid has one solution and can be reached by logic.

Two Not Touch in the New York Times

The New York Times began printing Star Battle in April 2020, under the name Two Not Touch. Jim Bumgardner announced it on the KrazyDad blog: starting on Monday 20 April 2020, his puzzles would appear in the print edition of the Times as Two Not Touch, with an easy and a medium puzzle every day from Monday to Saturday. He described the puzzle as one "which comes from the Netherlands".

The name says the rules in three words: two stars per row, column and region, and they do not touch. In an interview with The Examiner News on 30 April 2020, the Times crossword editor Will Shortz described Two Not Touch as "a grid-based logic puzzle designed by Jim Bumgardner" with "some similarities to KenKen", one of two new puzzles in the daily puzzle section. He linked the timing to the Times' own history: the paper first added its crossword in February 1942, after Pearl Harbor, as "an intelligent diversion", and he thought it fitting to add more puzzles during the spring of 2020.

Queens on LinkedIn, and the eight queens problem

In 2024 a one-star version of Star Battle reached a very different audience. LinkedIn added three daily games in May 2024, Pinpoint, Crossclimb and Queens, as Fortune reported. LinkedIn's help page for Queens gives its rules: each row, column and coloured region must contain exactly one crown, and crowns cannot be placed in adjacent cells, including diagonally. That is one-star Star Battle, with crowns for stars and colours for the outlines.

The name Queens points to a much older puzzle. The eight queens puzzle asks you to place eight chess queens on a chessboard so that no two attack each other. It was published by the chess composer Max Bezzel in 1848, and Franz Nauck published the first solutions in 1850, according to Wikipedia's article on the puzzle. It has 92 solutions, or 12 if you count rotations and reflections as one.

The two puzzles share the one-per-row and one-per-column idea, but they differ on diagonals. A chess queen attacks along the whole diagonal, so no two queens may share any diagonal at all. In Star Battle and in Queens, a star or crown only rules out the diagonal squares right next to it, and regions take the place of the long diagonals. Our post on the Queens puzzle and Star Battle compares the two games for players coming from LinkedIn.

One puzzle, many names

Star Battle now goes by several names, and they all describe the same idea: place stars (or crowns) so that every row, column and region has the same number and none touch.

NameWhere it is usedStars per row, column and region
Star BattleThe 2003 championship, competitions, puzzle magazines and sitesUsually 1, 2 or 3
Two Not TouchThe New York Times, from April 20202
QueensLinkedIn, from May 20241 (crowns, coloured regions)
StarsPuzzle Picnic1 (coloured regions)

The rules travel well because they need no language and no arithmetic. That was the point of the 2003 championship's design, and it is why the same puzzle sits comfortably in a world final, a newspaper and a phone app.

Frequently asked questions

Who invented Star Battle?

Hans Eendebak, a Dutch puzzle maker and organiser, invented Star Battle for the 2003 World Puzzle Championship in Arnhem, the Netherlands. The World Puzzle Federation's newsletter credits the championship puzzle to him, and his 2019 obituary names Star Battle among his classics.

Is Two Not Touch the same as Star Battle?

Yes. Two Not Touch is the name the New York Times uses for two-star Star Battle puzzles made by Jim Bumgardner of KrazyDad. Each row, column and region holds two stars, and no two stars touch.

Is LinkedIn's Queens the same as Star Battle?

Queens uses the rules of one-star Star Battle: one crown in every row, column and coloured region, and no two crowns in touching squares, diagonals included. The name comes from the chess puzzle about placing queens, which has a stricter diagonal rule.

When did Star Battle first appear?

Star Battle first appeared at the 12th World Puzzle Championship in 2003, held at Papendal near Arnhem. The World Puzzle Federation held its general assembly there on 16 and 17 October 2003.

Where to go next

Knowing where a puzzle comes from makes its design easier to see. Star Battle was built for a contest between solvers from many countries, so it has no clues to read and rewards pure logic. If you want to put that to use, our Star Battle strategies guide walks through the techniques in the order you will need them.

Puzzle Picnic's Stars is the one-star version, from a 6x6 grid on Easy to 9x9 on Expert, and it is one of the six games in the app's single daily puzzle, which rotates through them. The Stars page has the rules and a Play button.

Sources