Murder by the Dozen — pick a case and go and look at things Runs here
1986 · Thunder Mountain · System 6 · Mini vMac (Mac Plus) · 512×342 black and white
Guide updated September 2026
The opening screen is a grid of twelve numbered illustrations — a knife, a magnifying glass, a gun, a pair of hands — and a box saying "Welcome to Mystery Master! Select a case to solve…". Each number is a self-contained murder with its own town, suspects and solution.
The structure is closer to a puzzle book than to an adventure game. You move around a map of locations, question people, collect statements, and when you think you can prove it you name a suspect. There is no inventory and nothing to carry; the whole game is information.
Boots to the case selection grid. Click a number to begin that case.
Controls
| Mouse | Pick a case, choose locations, and select who to question |
| Menus | Review notes, check the time, and accuse |
Thunder Mountain was Mindscape's budget label. Mindscape's assets were dispersed after the company wound down and this has not been sold by anyone since the 1980s.
Archives
- Internet Archive — the Macintosh floppy this copy was made from.
How it works & what to expect
| Machine | Macintosh Plus, 512×342, black and white |
|---|---|
| System | The floppy's own — this disk carries the System it shipped with |
| Emulator | Mini vMac, compiled to WebAssembly |
| Saves | Inside the emulated Mac, in your browser |
Each case is short — half an hour to an hour — and there are twelve of them, so the disk has a lot more in it than its size suggests.
Take notes on paper. The game gives you statements from several people per case and the contradictions between them are the solution; holding four alibis in your head across a dozen locations does not work.
Why it is remembered
Twelve games on one disk. The anthology structure was unusual and it is the reason this stayed in circulation: you can finish one on a lunch break, and finishing one does not exhaust the disk.
It came from a book series. Murder by the Dozen began as printed mystery puzzles, and the computer version is a faithful adaptation rather than a game with a mystery theme bolted on. The cases are properly constructed.
Thunder Mountain was the budget line. Mindscape's cheap label mostly reissued other people's games; this is one of the few things it published that was worth the shelf space on its own terms.
Getting started
Start with case one. They are not connected but they do get harder, and the first is the one that teaches you the interface.
Visit every location before you question anyone twice. Statements change depending on what you have already found, and going around once cheaply is better than going deep in the wrong place.
Write down who says they were where, and when. Every case turns on a timeline that does not fit.
Questions people ask
How many cases are there?
Twelve, each self-contained, chosen from the grid on the opening screen.
How long is a case?
Half an hour to an hour, which makes this one of the easier things here to play in a short sitting.
Is it based on a book?
Yes — the Murder by the Dozen printed mystery puzzles, adapted faithfully.
Do I need to take notes?
Yes, in practice. Every case is solved by spotting a contradiction in a timeline.
Can I save?
Yes. Saves live inside the emulated Macintosh in your browser.
Is there a parser?
No. It is entirely mouse-driven — pick locations, pick people, pick a suspect.
