How to Play Thermometers

Overview

Thermometers is a logic puzzle where you fill thermometers with mercury. Each thermometer fills from its bulb (rounded end) toward its tip, and the row/column clues tell you how many cells should be filled in each line.

Video Tutorial

Rules

  • 1Thermometers have a bulb (rounded end) and a tip (other end).
  • 2Mercury fills from the bulb toward the tip - it must be continuous!
  • 3If a cell is filled, all cells between it and the bulb must be filled too.
  • 4Edge numbers show how many cells are filled in that row or column.
  • 5Thermometers can be empty, partially filled, or completely filled.

Controls

ClickFill cell with mercury
Click againMark cell as empty (×)
Click againClear cell (unknown)
Ctrl+ZUndo last move

Solving Strategies

Start with 0 Clues

If a row or column has 0, mark all cells in that line as empty (×).

Maximum Fills

If a clue equals the total cells in that line, fill them all.

Continuity Rule

If you fill a cell, all cells between it and the bulb must also be filled.

Mark Empty Cells

If filling a cell would exceed a clue, mark it empty to help deduce others.