This chapter describes features that are common to all the games.

Common actions

These actions are all available from the ‘Game’ menu and via keyboard shortcuts, in addition to any game-specific actions.

(On Mac OS X, to conform with local user interface standards, these actions are situated on the ‘File’ and ‘Edit’ menus instead.)

New game (‘N’, Ctrl+‘N’)

Starts a new game, with a random initial state.

Restart game

Resets the current game to its initial state. (This can be undone.)

Load

Loads a saved game from a file on disk.

Save

Saves the current state of your game to a file on disk.

The Load and Save operations preserve your entire game history (so you can save, reload, and still Undo and Redo things you had done before saving).

Print

Where supported (currently only on Windows), brings up a dialog allowing you to print an arbitrary number of puzzles randomly generated from the current parameters, optionally including the current puzzle. (Only for puzzles which make sense to print, of course – it's hard to think of a sensible printable representation of Fifteen!)

Undo (‘U’, Ctrl+‘Z’, Ctrl+‘_’, ‘*’)

Undoes a single move. (You can undo moves back to the start of the session.)

Redo (‘R’, Ctrl+‘R’, ‘#’)

Redoes a previously undone move.

Copy

Copies the current state of your game to the clipboard in text format, so that you can paste it into (say) an e-mail client or a web message board if you're discussing the game with someone else. (Not all games support this feature.)

Solve

Transforms the puzzle instantly into its solved state. For some games (Cube) this feature is not supported at all because it is of no particular use. For other games (such as Pattern), the solved state can be used to give you information, if you can't see how a solution can exist at all or you want to know where you made a mistake. For still other games (such as Sixteen), automatic solution tells you nothing about how to get to the solution, but it does provide a useful way to get there quickly so that you can experiment with set-piece moves and transformations.

Some games (such as Solo) are capable of solving a game ID you have typed in from elsewhere. Other games (such as Rectangles) cannot solve a game ID they didn't invent themself, but when they did invent the game ID they know what the solution is already. Still other games (Pattern) can solve some external game IDs, but only if they aren't too difficult.

The ‘Solve’ command adds the solved state to the end of the undo chain for the puzzle. In other words, if you want to go back to solving it yourself after seeing the answer, you can just press Undo.

Quit (‘Q’, Ctrl+‘Q’)

Closes the application entirely.

Preferences

Where supported, brings up a dialog allowing you to configure personal preferences about a particular game. Some of these preferences will be specific to a particular game; others will be common to all games.

One option common to all games allows you to turn off the one-key shortcuts like ‘N’ for new game or ‘Q’ for quit, so that there's less chance of hitting them by accident. You can still access the same shortcuts with the Ctrl key.

Specifying games with the game ID

There are two ways to save a game specification out of a puzzle and recreate it later, or recreate it in somebody else's copy of the same puzzle.

The ‘Specific’ and ‘Random Seed’ options from the ‘Game’ menu (or the ‘File’ menu, on Mac OS X) each show a piece of text (a ‘game ID’) which is sufficient to reconstruct precisely the same game at a later date.

You can enter either of these pieces of text back into the program (via the same ‘Specific’ or ‘Random Seed’ menu options) at a later point, and it will recreate the same game. You can also use either one as a command line argument (on Windows or Unix); see section 2.4 for more detail.

The difference between the two forms is that a descriptive game ID is a literal description of the initial state of the game, whereas a random seed is just a piece of arbitrary text which was provided as input to the random number generator used to create the puzzle. This means that:

Descriptive game IDs tend to be longer in many puzzles (although some, such as Cube (chapter 4), only need very short descriptions). So a random seed is often a quicker way to note down the puzzle you're currently playing, or to tell it to somebody else so they can play the same one as you.
Any text at all is a valid random seed. The automatically generated ones are fifteen-digit numbers, but anything will do; you can type in your full name, or a word you just made up, and a valid puzzle will be generated from it. This provides a way for two or more people to race to complete the same puzzle: you think of a random seed, then everybody types it in at the same time, and nobody has an advantage due to having seen the generated puzzle before anybody else.
It is often possible to convert puzzles from other sources (such as ‘nonograms’ or ‘sudoku’ from newspapers) into descriptive game IDs suitable for use with these programs.
Random seeds are not guaranteed to produce the same result if you use them with a different version of the puzzle program. This is because the generation algorithm might have been improved or modified in later versions of the code, and will therefore produce a different result when given the same sequence of random numbers. Use a descriptive game ID if you aren't sure that it will be used on the same version of the program as yours.
(Use the ‘About’ menu option to find out the version number of the program. Programs with the same version number running on different platforms should still be random-seed compatible.)

A descriptive game ID starts with a piece of text which encodes the parameters of the current game (such as grid size). Then there is a colon, and after that is the description of the game's initial state. A random seed starts with a similar string of parameters, but then it contains a hash sign followed by arbitrary data.

If you enter a descriptive game ID, the program will not be able to show you the random seed which generated it, since it wasn't generated from a random seed. If you enter a random seed, however, the program will be able to show you the descriptive game ID derived from that random seed.

Note that the game parameter strings are not always identical between the two forms. For some games, there will be parameter data provided with the random seed which is not included in the descriptive game ID. This is because that parameter information is only relevant when generating puzzle grids, and is not important when playing them. Thus, for example, the difficulty level in Solo (chapter 11) is not mentioned in the descriptive game ID.

These additional parameters are also not set permanently if you type in a game ID. For example, suppose you have Solo set to ‘Advanced’ difficulty level, and then a friend wants your help with a ‘Trivial’ puzzle; so the friend reads out a random seed specifying ‘Trivial’ difficulty, and you type it in. The program will generate you the same ‘Trivial’ grid which your friend was having trouble with, but once you have finished playing it, when you ask for a new game it will automatically go back to the ‘Advanced’ difficulty which it was previously set on.

The ‘Type’ menu

The ‘Type’ menu, if present, may contain a list of preset game settings. Selecting one of these will start a new random game with the parameters specified.

The ‘Type’ menu may also contain a ‘Custom’ option which allows you to fine-tune game parameters. The parameters available are specific to each game and are described in the following sections.

GridPuzzles