Frequently Asked Questions

What is Numbun?

Numbun is a browser-based number guessing game. The goal is to find a hidden number made of unique digits by using feedback after each guess: + means a correct digit in the correct position, and - means a correct digit in the wrong position. Numbun is free, ad-free, privacy-conscious, and designed to work in the browser, including offline play.

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Is Numbun the same as Bulls and Cows?

Numbun belongs to the same traditional game family as Bulls and Cows. The shared idea is deductive code-breaking: a secret number or code is hidden, and the player uses partial feedback to eliminate wrong possibilities and find the answer. Numbun uses + / - clues, while Bulls and Cows uses bulls and cows [1], [2].

Is Numbun the same as Mastermind?

Numbun is Mastermind-like, but not identical to classic Mastermind. Mastermind is usually played with colored pegs, while Numbun uses numbers with unique digits. Both belong to the same broader code-breaking and deduction-game tradition [3], [4].

What do the + and - clues mean?

A + means one digit is correct and in the correct position. A - means one digit is part of the secret number but is in the wrong position. The result shows only the totals; it does not say which specific digit produced each + or - clue. For example, if the secret number is 1234 and the guess is 1456, the digit 1 gives + because it is correct and in the right place, while digit 4 gives - because it exists in the secret number but is in the wrong place.

Why are the digits unique?

Numbun uses numbers with non-repeating digits to keep the deduction clean and readable. This rule is also common in several related variants such as Bulls and Cows, 1A2B, AB, and many number-based Mastermind-style games [2], [5].

Is Numbun a luck game or a logic game?

Numbun is mainly a logic and deduction game. Luck may affect the first guess, but strong play depends on using each clue to remove impossible numbers, compare alternatives, and make better next guesses. This is why games in the Mastermind / Bulls and Cows family have been studied in mathematics, computer science, and reasoning research [3], [4], [6], [7].

What skills can Numbun help practice?

Numbun can help players practice deductive reasoning, hypothesis testing, elimination, strategic trial-and-error, attention to feedback, and systematic problem solving. Educational research on related mind games, including the Mastermind-like game PappaLOTTO, reports promising but preliminary evidence for supporting children's strategic and reasoning abilities [8], [9].

Is there academic research about games like Numbun?

Yes. The broader family that includes Bulls and Cows, 1A2B, Mastermind, AB games, MOO, Hit & Blow, and related variants has been studied in several contexts. Some research focuses on education and reasoning skills; other research studies the game as a combinatorial search, algorithmic, or computational complexity problem [3], [4], [6]–[8], [10]–[14].

Has this type of game been used in schools?

Yes. Bottino et al. studied computer mind games at primary school level and included PappaLOTTO, a Mastermind-style game, as one of the tools used to support strategic and reasoning abilities. A Turkish educational resource, Oyunsever İzmir Zekâ Oyunları 1, also includes Sayı Tahmini as a school-oriented reasoning and strategy game [8], [9].

Does Numbun improve intelligence or school grades?

The safest evidence-based answer is that Numbun can support reasoning practice, but it should not be claimed to directly increase intelligence or guarantee better grades. Existing research on related games suggests educational potential, especially for reasoning and strategy, but the direct classroom evidence is still limited and should be described carefully [8], [9].

What are other names for this game around the world?

The same game family appears under many names, including Bulls and Cows, 1A2B, 猜數字, AB game, Hit & Blow, MOO, Number Baseball, Sayı Tahmin Oyunu, Picas y Fijas, Taureaux et Vaches, Bullen und Kühe, Touros e Vacas, Быки и коровы, Numerino, and Numerello. The names differ by region and language, but the core mechanic is the same: find a hidden code using partial feedback [2], [5], [11].

What game modes does Numbun include?

Numbun's core modes are Normal, Blind Start, and Cold Case. Normal shows feedback after every guess. Blind Start asks you to enter a chosen number of guesses without feedback, then reveals those results together before regular play continues. Cold Case begins with several evaluated, computer-generated guesses and gives you fewer player attempts to complete the deduction. Free Play supports secret lengths from 2 to 9 digits, while Daily Puzzle and Daily Case give everyone the same date-based challenge.

Can I play earlier daily games or revisit completed days?

Yes. Daily Puzzle and Daily Case each include a calendar and previous/next controls covering every available date from Numbun's first daily game through today. The calendar marks solved, lost, and in-progress days. You can open any available date, play a missed or previously unplayed day, and resume a game that is still in progress.

When you revisit a completed day, Numbun restores its saved guesses, result, and game-specific whiteboard. Completed daily games cannot be reset or played again; their whiteboards become read-only so you can review your reasoning without changing the original record.

Can I share my result like Wordle?

Yes. A finished result can be turned into a compact, spoiler-light grid: 🟩 means a digit was correct and in the correct position, 🟨 means it was present in another position, and ⬛ means it was absent. Each row also includes its + / - score, and a winning row ends with 🎉. The share shows the game or mode, puzzle number when applicable, guess count, and time without printing your guessed digits or the secret number.

Numbun · Daily #44
🧠 5/10 · ⏱️ 02:48
⬛🟩⬛🟨  +1, -1
🟨🟨⬛🟨  -3
🟩⬛⬛⬛  +1
🟩⬛🟨🟨  +1, -2
🟩🟩🟩🟩  +4 🎉

Daily Puzzle and Daily Case results can be shared after a win, an attempt-limit loss, or giving up; unsuccessful shares are clearly labeled as Lost or Gave up and invite others to try. In Free Play, Blind Start, and Cold Case, a hint-free win can include a challenge link that lets friends play the same game, while the result-only option leaves out the link.

What statistics can I see, and what can I learn from them?

The statistics view summarizes total, completed, and abandoned games; wins and win rate; current and best winning streaks; total playtime; average, median, and best completion time; average time between guesses; guess distribution; and hint usage. Detailed charts compare results by mode, game type, digit count, and exact setup, including games, wins, losses, abandoned games, win rate, average and best guesses, and time.

The 30-day activity board uses stronger color for more games and a dot for a day with at least one win. Select a day in the board or time chart to see its games, wins, and playtime. This can reveal how consistently you play, whether longer sessions improve accuracy, and which days were most active.

Use the comparisons to test your own strategy: check whether Normal, Blind Start, or Cold Case suits you best; how performance changes as the secret gets longer; which setup gives you the best balance of speed and accuracy; and how often you rely on each hint type. The data describes your play on this device, so treat patterns from only a few games as early signals rather than firm conclusions.

How do the whiteboard and its tools work?

Every game has its own locally saved whiteboard. Use the pen, eraser, and text tools for notes; Select to move or resize items; and Pan to move around the canvas. You can change ink color and size, switch between light and dark boards, zoom, undo or redo, clear the board, and download it. Insert game panel adds the current guesses and + / - results to the board and keeps that panel in sync with the game.

The 0–9 tool inserts a digit strip for fast elimination. Tap a digit once to strike it out as eliminated, again to circle it as confirmed, and a third time to clear the mark. These are your own reasoning notes rather than automatic hints: strike digits you have ruled out, circle digits you believe belong to the secret, and use text or the pen to track possible positions and candidate guesses.

A board is editable while its game is in progress. After the game ends it becomes read-only, but you can still reopen, inspect, pan, zoom, and download it. Revisiting a Daily Puzzle or Daily Case date opens that day's matching board. Whiteboard data stays on your device.

Can I play Numbun offline?

Yes. Numbun is designed as a browser-based game with offline support, so it can continue working after it has loaded, depending on the user's device and browser behavior.

Does Numbun collect personal data?

Numbun does not collect or store personal data about visitors or players and does not use cookies or similar identifiers. Game progress, settings, statistics, and whiteboard notes stay locally on your device. Numbun uses Plausible Analytics only to understand aggregate usage trends without cookies or persistent identifiers. For more details, see the privacy page.

Is there a best strategy for Numbun?

There are strong strategies, but no single simple rule is best for every situation. A good general strategy is to make guesses that reduce the number of possible secret numbers as much as possible. This idea is related to classic research on Mastermind strategies, including Knuth's well-known five-guess result for the classic Mastermind configuration [3], [12], [13].

Why is Numbun educational?

Numbun is educational because it encourages players to reason from evidence instead of guessing randomly. Each clue forces the player to revise assumptions, eliminate contradictions, and plan the next move. That makes it a compact practice environment for logical reasoning, structured thinking, and problem solving [3], [8], [9].