Puzzle, board and card games
Falling-block and logic puzzles, board games, card games, and the small games that shipped with operating systems. Board and card games are turns and choices; action puzzles (Tetris, Lemmings) are streams with controls. They are often small, so they make good first projects for practising the whole method.
Reference games
| Game | Year, platform | Why it is a good example |
|---|---|---|
| Tetris | 1989, NES and Game Boy | A random piece generator, gravity tables per level, input delays, all well documented |
| Lemmings | 1991, Amiga and DOS | Each lemming a small state machine on a pixel-exact terrain mask |
| The Incredible Machine | 1993, DOS | A small physics engine and parts with rules |
| Microsoft Solitaire and FreeCell | 1990 onward, Windows | Shuffles from a seed: FreeCell's numbered deals come from the C runtime's rand |
| Chessmaster | 1986 onward | A search engine with an opening book, a board and a rules core |
| Minesweeper | 1990 onward, Windows | Board generation from a random seed, the first-click rule |
Projects to learn from
Few public reimplementations exist for this family: most games are small enough to rebuild from observation, and many clones copy only the idea. Two kinds of work are useful:
| Work | What it shows |
|---|---|
| Disassemblies of NES and Game Boy Tetris by the speedrunning community | Exact piece randomisers, gravity, entry delays; the rules that competitive play depends on |
| Write-ups of FreeCell deal numbers | How a shuffle from the C runtime's rand makes numbered deals reproducible |
The rule set
What must be exact. The random generator and how it picks pieces, cards or mines (with any "bag" or anti-repeat rule); the rules of legal moves; scoring; timers and delays in frames.
Where the rules live. Almost all in code, and small. Levels and puzzles are data. Card deals and boards come from the random generator, often the C runtime's rand seeded with a number shown to the player (a deal number) or with the clock.
Inputs. Keys or clicks, sometimes with repeat delays (auto-shift in Tetris) that the port must copy. Record per frame for action puzzles, per move for board and card games.
Interface. Simple. Players know where everything is, so keep every position exact. Animations (a card flying, a line clearing) may block input for a number of frames. Port those frame counts.
Time and determinism. Turn-based games wait. Action puzzles run at the console's or the screen's refresh rate; gravity is a table of frames per row.
How to verify. Emulate the generator and compare thousands of deals or pieces from many seeds. Play recorded games move by move and compare the board.
Pitfalls.
- A generator seeded from the clock: record the seed, or make it an input.
- Animation frames that delay input (the "entry delay"), easy to miss without frame stepping.
- Scores that overflow or cap at the number of digits shown.
Connections
- Arcade action: frame-exact input for action puzzles.
- Adventure: logic that waits for the player.
- Random number generators: most of what must be exact in these games.