FALSUM guide
Logic puzzles on paper or on screen: what each format gives you
Paper wins when a case requires marking and crossing out, because you can annotate the grid without losing the overview. Screen wins on instant checking and saved progress. For single-reading cases the medium barely matters; for cases with many crossed constraints, a pencil is still faster.
What paper does well
Annotating is part of solving. Marking dots and crosses on the grid itself keeps the state of your reasoning visible, and that external memory is exactly what lets you hold several constraints at once. On screen that annotation is usually mediated by an interface deciding what you may mark.
Paper also supports the table: three people around one page see the same thing and can point. That is hard to reproduce on a phone.
What the screen does well
- Checks instantly whether a hypothesis breaks a constraint, without redoing the grid.
- Saves progress and lets you pick a case back up where you left it.
- Gives graded hints with no risk of accidentally reading the solution on the next page.
- Lets you try before buying, which is the most honest use of the format.
What you lose when switching
The screen takes away one specific thing: the overview. A whole grid on a page is taken in at a glance, and that global look is what surfaces relationships between distant areas. On a phone the same grid is traversed in parts, and the reasoning turns local without the player noticing.
Paper takes something away too: the checking. An annotation error at step three surfaces twenty minutes later, when you no longer know where it started. It is frustrating in a way that teaches nothing, and it is exactly what the screen handles well.
Which format for which case
- Single-reading cases with no annotation: either, whichever is to hand.
- Cases with many crossed constraints: paper, for the overview.
- Learning the rules of a new mechanic: screen, for instant feedback.
- Solving in a group around a table: paper, unless you have a large tablet.
- Short interrupted sessions, on public transport: screen, because it saves progress.
In practice they work together
The sensible split is to start on screen to learn the rules, with instant checking and no fear of being wrong, and move to paper when cases get longer. It is why RASTROS exists in both forms: there are cases playable in the browser, free and with graded hints, and a book of 100 cases with a pencil.