Combinations: how we make a word game where every word counts

Combinations is a daily word game built from pieces of words. You get twelve tiles, each holding a short piece of a word two to four letters long, and a hidden list of real words that can be made by joining them. Find enough of those words to reach the goal and the puzzle is solved. It sounds simple, and it is meant to feel simple. Behind every grid, though, there is a fair amount of checking, because a word game is only fun when it plays fair.

How to play Combinations

Tap tiles in order to spell a word, then press Submit. pl followed by ay makes play. Tap a selected tile again to remove it, or press Backspace on a keyboard. Each tile can be used once per word, and a word needs at least two tiles.

A word scores its number of letters multiplied by the number of tiles minus one. Two-tile words score their length, three-tile words score double, and words made from four or more tiles count as bonus words.

The first star lights up with your first word, the next three at a quarter, half and three quarters of the goal, and the fifth when you reach it. After that you can keep going and hunt for every word in the list.

Why every real word has to count

The fastest way to spoil a word game is to reject a word the player knows is real. You spot stared, tap it in carefully, and the game says no. From that moment every guess feels uncertain. So the answer list for a Combinations puzzle is not written by hand. It is calculated.

For each puzzle we look at every way of joining two, three, four or five different tiles. With twelve tiles that is 108,372 possible tile orders. Every common word that turns up among them goes into the answer list. If a real everyday word can be built from the tiles, it counts. Rare words, names and abbreviations are left out, and words that could offend are blocked completely: a puzzle is thrown away if one of them could be spelled.

How a Combinations puzzle is made

1. 1Start from a real word. Each puzzle begins with a common word of seven to twelve letters, split into three or four pieces. Those pieces become the first tiles.
2. 2Add pieces that join well. The rest of the twelve tiles are chosen from thousands of common word starts and endings. The generator then swaps tiles hundreds of times, keeping every change that lets the tiles build more everyday words.
3. 3Apply the house rules. Every tile has at least two letters and is used by at least two words. A puzzle needs between 22 and 60 words, at least six three-tile words and at least one bonus word. Every word can be built in exactly one way, and no offensive word can be built at all.
4. 4Check it twice. A second, independent program tries every ordered pick of two to five tiles and compares what it finds with the answer list. Only puzzles that match perfectly are scheduled.

A goal you can always reach

The goal is set to half of all the points available from two-tile and three-tile words. Bonus words make the score climb faster, but you never need one to solve the puzzle. A careful player can always get there by working through the shorter combinations.

The daily puzzle changes at midnight in your own time zone, and everyone gets the same grid for the same date. Puzzles are prepared well in advance, with more than 800 daily grids ready in each language. If you miss a day, the calendar lets you go back and play it.

Tips for finding more words

• Start with the busiest tiles. The number on each tile counts the words that still use it. Tiles with high numbers are the best places to start.
• Look for endings. Pieces such as ed, ing and er turn one word into several. Once you find a short word, try adding an ending to it.
• Try every tile as a first piece. Words are built in the order you tap, so the same tiles can make different words when you change which one comes first.
• Shuffle when you get stuck. Moving the tiles around breaks the patterns your eyes have settled on and often shows a pairing you missed.
• Save your hints. You get three per puzzle. A hint outlines the first tile of a common word you have not found yet, so it is most useful near the end.

Three languages, three word lists

Combinations is available in English, French and German. Each language has its own list of common words and its own puzzles, so a French grid is built for French words rather than translated from English. Accented letters such as é or ü are real letters on the tiles. For practice between daily puzzles, Combinations Unlimited has hundreds of extra grids in every language.

Try it yourself

Today’s puzzle is waiting at combinations.gg. Start with the tile that has the highest number, look for endings, and see how far past the goal you can get.