How to play?

LULLO GAME is an online game designed to promote skills related to combinatorics and deduction. The game requires you to guess a number, a word, or an equation based on successive attempts. In particular, after each attempt, the player is informed through colors which characters they guessed correctly and if they are in the right position.

On the home page, the user also chooses whether they want to guess the hidden expression using six attempts (challenge mode) or an unlimited number of attempts (practice mode).

NUMBERS

In NUMBERS mode, the user must guess a hidden number. In level 1 the number has 4 digits, in level 2 it has 5 digits, and in level 3 it has 6 digits. The user starts by entering a number of their choice and is given visual feedback. Referring to the attempt 7 3 2 6 in the following image, the 3 is colored purple because it is a correct digit in the right place. The 6 is yellow because it is contained in the hidden number but in a different position. The 7 and the 2 are gray, so they are not present in the secret number.

A possible next move for the user could be, for example, 6 3 1 4. We also specify that in the solution, 0 will never appear in the first position and that in levels 2 and 3, the same digit may appear multiple times.

WORDS

In WORDS mode, the user must guess a hidden word. In level 1 the word has 4 letters, in level 2 it has 5 letters, and in level 3 it has 6 letters.

For each attempt, the word entered must be a valid word: in other words, the game will only accept the attempt if the word exists in the dictionary (verb forms, plural nouns, etc., are allowed). It is therefore not possible to proceed by entering random sequences of letters.

Referring to the example below with the word FAME, we notice that the letter A and the letter E are purple (correct and in the right position). The letter M is yellow (it is present but needs to be moved), while the F is gray (it does not appear in the target word).

A plausible word for the next attempt is, for example, MARE.

The WORDS mode is inspired by the game WORDLE.

EQUATIONS

This last mode is the most interesting from a mathematical perspective because the written expression must actually be a correct equation.

The player must enter a sequence consisting of numbers and operations (+, -, ×, :) that always contains one and only one equals sign (=). The game will only accept the attempt if the value of the expression to the left of the equals sign matches the value of the expression to the right.

In the following image, you see the attempt 3 + 4 = 7. The symbols + and = are purple (correct and in the right position). The number 4 is yellow (present but out of place), while 3 and 7 are gray (absent).

In level 1, equations involve addition, subtraction, and multiplication; in level 2, division is added and the length of the expression increases.

Finally, we emphasize that when evaluating expressions, multiplications and divisions must be performed first, followed by subtractions and additions. Furthermore, operations can appear both to the left and to the right of the equals symbol (e.g., 3 + 5 = 2 × 4).

The EQUATIONS mode is inspired by the game NERDLE.

MASTERMIND MODE

By playing with two people and selecting the "infinite attempts" option, you can make the challenge more difficult by turning Lullo Game into the classic Mastermind. One player operates the computer and enters the attempts dictated by the other. After each attempt by the second player, the one holding the device communicates only the number of purple and yellow squares obtained without showing the grid, meaning without specifying which squares or which characters they are (for example, they might say "2 purple and 1 yellow").

Guessing the hidden expression is very complex and requires a high number of attempts. Once the player has guessed the hidden expression, the roles are swapped. Alternatively, you can play against each other on two devices (each player plays both roles simultaneously, taking turns for each attempt), and the one who guesses in the fewest number of attempts wins.