Sumtowers

A brand-new logic puzzle — free online or as a large-print book

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Place 1..N once per row and column. An edge number is the SUM of the towers visible from that side (a tower hides shorter ones behind it). Tap a cell, then tap a number.

Prefer paper?

Sumtowers — 130 puzzles per volume (Easy, Medium, Hard), as a large-print paperback.

How Sumtowers works
Each row and each column must contain every tower height from 1 to N exactly once. Looking in from an edge, you can see a tower only if it is taller than all towers before it. The number on that edge is the SUM of the heights of the towers you can see. Example: a row 2 1 4 3 — from the left you see the 2 and the 4 (the 1 and 3 hide), so the left clue is 2 + 4 = 6. The tallest tower is always visible, so every clue is at least N. Every puzzle has exactly one solution, reachable by logic alone.