This is a logic game where there is a hidden rule that fits some triplets of numbers and not others.
Each case comes with a base case that fits the hidden rule.
Each domino represents a number. The black dominoes represent negative numbers.
You can make experimental tests to see if they fit the rule by clicking the "First", "Second", and "Third" buttons to choose which triplet in your guess you want to add dominoes to and then clicking dominoes in the domino bank. You can switch between the triplet you are adding numbers to by clicking another button of the 3. If you choose any black/negative dominoes for a triplet, that place of the triplet will be interpreted as negative.
You can use keys 1,2 and 3 to quick select "First", "Second" and "Third."
Your guesses will appear below "Past Guesses" and will stay if you switch to another level so that you can come back to a level and still see what you've guessed in the past.
When you've performed all the further experimental tests you want, you can test what you think the rule is against 5 cases. If you correctly identify each case as fitting with the rule (or not), you pass the level.
If you're stuck, you can click the shake domino icon to shuffle the base case that is being displayed to another one that fits the rule.