About Milo Marwick
Milo Marwick is the name behind a series of logic puzzle books and this free puzzle site. The site has 3D spatial reasoning puzzles (a daily 3D puzzle game, a daily test, cube nets, counting cubes and mental rotation) and Train Tracks, with a daily puzzle, a library of 140 graded puzzles, printable sheets and a solver. The books are listed on the books page.
Everything you need is on the page
Every Milo Marwick puzzle is built around one promise: you can solve it by thinking alone. There is no trivia, no outside knowledge and no trick that depends on reading the setter's mind.
- One answer you can prove. Every Train Tracks grid and every 3D question has exactly one solution, and you can reach it step by step from the clues.
- Every clue matters. Puzzles carry only the pieces they need. If a clue is there, it is there for a reason.
- No guessing. Easier puzzles never need trial and error. Harder ones may ask you to test a single "what if", but the logic always decides.
The 3D puzzles
The 3D puzzles follow the conventions of the book THINK IN 3D: solids are stacks of cubes, the views are the top, the front and the left side, thick lines mark every change of depth, and anything the views cannot show is taken to be solid ("hidden means solid"). Each multiple-choice question has exactly one correct option. In the 3D building game, any build whose three views match wins.
How levels are graded
The level tells you the hardest technique you will need, not just the grid size:
| Level | Grid | Hardest technique allowed |
|---|---|---|
| Easy (Curious) | 6×6 | Solvable with counting, the two-connections rule and the no-loop rule. |
| Medium (Clever) | 8×8 | Mostly counting and the loop rules on a bigger grid; a few puzzles also need the crossing-parity rule. |
| Hard (Devious) | 10×10 | Usually needs a short “what if” test on a single cell or connection. |
| Expert (Milo) | 12×12 | Fewest clues; expect longer chains of reasoning. Still exactly one solution. |
The techniques are explained, with diagrams, on the strategy page.
Found a puzzle that breaks the promise?
A logic puzzle is only fun if it is fair. If you ever find one that seems to have two answers, or no way in without guessing, please tell us which one and we will look at it.
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