Rules
Two-Arm Scales was a prize match in The Devil’s Plan. Players were split into rooms and given coloured minerals of different weights. Using balances, and the readings shared between rooms, they had to work out every weight.
The blocks
There are five colours: red, yellow, green, blue and purple. Each colour weighs a different whole number of grams from 1 to 20. You hold two blocks of each colour, and the weight of one colour is given at the start.
A weighing
- Put at least one block on each pan. You can use up to two blocks of each colour.
- Press Weigh. The scale tips to the heavier side, or stays level if both pans weigh the same.
- The reading goes into the log as, for example,
R R > G B: two reds are heavier than a green and a blue.
Our version
- The show’s rooms shared their readings. Here the log starts with three shared readings, free of charge.
- Your score is the number of weighings you make. A wrong answer counts as two more.
- Every puzzle is checked by a solver, so it can always be finished.
- Possible weights: with this setting on (the default), each colour shows the range of weights that still fit every reading. Turn it off to keep track yourself.
- The Daily puzzle is the same for everyone each day.
Strategy
Start from the known block. Comparing one or two of the known blocks with another colour cuts its range in half at once.
Use doubles. Two blocks of a colour against one of another tests “is A more than half of B?”, a finer question than a single block can ask.
Aim for a balance. A level scale is an exact equation, often worth several tilts. Try a combination that just might be equal.
Split, do not confirm. A weighing whose result you can already predict tells you nothing. Pick one where both outcomes are possible.