Who picks odd or even in the game?

One player calls ‘odd’ or ‘even’ before the reveal. In our online game the player picks against the CPU; in 2-player mode only Player 1 makes the call (Player 2 just chooses their fingers); and in Battle mode it is automatic.

Is there strategy in Odds and Evens?

Yes. Some people repeat habits (the same fingers or the same parity), and that can be exploited. If you can predict how many fingers your opponent will show, you can adjust your own fingers to control whether the total is odd or even.

What is Odds and Evens called in other languages?

In English it is called ‘odds and evens’, in Spanish ‘par o impar’ (sometimes ‘pares y nones’) and in Portuguese ‘par ou ímpar’. In ancient Rome it was known as ‘ludere par impar’. It is a very old game that is still played with few changes.

Is Odds and Evens a game of luck or strategy?

If both players choose at random, each side wins 50% of the time: 18 of the 36 finger combinations give an even total and 18 give an odd one. Against humans, though, some people repeat habits (for example, showing the same fingers almost every time), and that can be exploited.

How to Play Odds and Evens: Rules, History & Strategy

Q: How do you play Odds and Evens?

One player secretly picks ‘odd’ or ‘even’. Then both players simultaneously show 0 to 5 fingers on one hand. If the combined total of fingers shown matches the player's choice (odd or even), that player wins the round.

How do you play Odds and Evens?

Odds and Evens is a two-player game. The rules are simple:

One player secretly picks "odd" or "even" before the reveal
Both players simultaneously show 0 to 5 fingers on one hand
The fingers from both hands are added together
If the total is even and the player picked "even", they win. If it's odd and they picked "odd", they win. Otherwise the other player wins.

Who picks odd or even

In the traditional game, someone calls “odd” or “even” before the reveal. In our online Odd or Even game, the player picks against the CPU; in 2-player mode (same device) only Player 1 makes the call and Player 2 just chooses their fingers; in Battle mode the call is automatic.

Example round

Player A secretly picks "even". Player A shows 3 fingers. Player B shows 2 fingers. Total = 3 + 2 = 5. 5 is odd → Player A loses the round.

Second round: A picks "odd". A shows 4 fingers. B shows 1 finger. Total = 5. 5 is odd → Player A wins.

Note: showing 0 fingers (a closed fist) is valid. A total of 0+0=0 is even — whoever picked "even" wins that round.

Want to try it? Play Odd or Even online for free against the CPU or a friend, and use the parity table in the strategy section.

History: from Rome to the world

Ancient Rome: ludere par impar

The game appears in Latin texts under the name ludere par impar — "to play odd or even". The poet Horace mentions it in his Satires as a typical children's pastime. In the original Roman version, instead of fingers, players guessed whether a closed hand hid an even or odd number of nuts, beans or coins; the finger version is the modern form.

The Greek world

Ancient sources suggest the Greeks also knew a game of guessing odd or even, usually called artiasmos (from artios, “even”).

What it's called

English: Odds and evens
Spanish: Par o impar, sometimes “pares y nones”
Portuguese: Par ou ímpar
Latin: Ludere par impar

Strategy: is there a way to win more?

Odds and Evens has more of a luck component than Chopsticks or Morra — but it isn't fully random against humans.

Your opponent's habits

Some people fall into habits: always the same number of fingers, or always the same parity. The extremes (0 and 5) can feel "odd" and some players avoid them. If you spot a habit like that, use it: all you need to anticipate is the parity of what your opponent will show (see the parity table below).

Influencing the total with your own fingers

If you think your opponent will show 3 fingers (odd), and you picked "even": you need the total to be even. To do that, show an odd number (1, 3 or 5) — odd + odd = even. If you think they'll show 2 (even) and you picked "odd": show an odd number too — even + odd = odd. The parity table is simple:

Even + Even = Even
Odd + Odd = Even
Even + Odd = Odd
Odd + Even = Odd

Watching for patterns

Every round is independent: your opponent showing 2 fingers three times in a row does not mean they are about to switch. What helps is checking whether they have a real habit, such as showing the same parity almost every time, and whether it holds. If you cannot find one, the best play is to choose your own parity at random (see the next section).

The maths behind it: why Odds and Evens is 50/50

Each player shows 0 to 5 fingers: three even numbers (0, 2, 4) and three odd ones (1, 3, 5). If both choose at random, the total is even in 18 of the 36 possible combinations and odd in the other 18 — exactly 50% each way.

What decides the round is not the exact number of fingers but the parity of each one. The player who called "even" wins when both show the same parity (even+even or odd+odd); the player who called "odd" wins when the parities differ. It is the same structure as the textbook game matching pennies: the best defence against an attentive opponent is to pick your parity at random, half and half. Any habit — always showing 3, say — can be exploited.

You called	You think your opponent will show	Show
even	an even number (0, 2 or 4)	an even number
even	an odd number (1, 3 or 5)	an odd number
odd	an even number (0, 2 or 4)	an odd number
odd	an odd number (1, 3 or 5)	an even number

You only need to predict your opponent's parity, not the exact number — so noticing whether they alternate between even and odd is worth more than counting fingers.

Odds and Evens as a teaching tool

Odds and Evens can help teach the concept of odd and even numbers to young kids. Adding two numbers and determining parity becomes concrete and meaningful when there's a "win or lose" outcome attached. It can be used in the classroom to introduce arithmetic in a playful way.

If you're looking for more no-materials games for the classroom, you might also like Chopsticks (you can also play Chopsticks online; addition and strategy) and Morra (fast addition from 2 to 10).

🤞 Play Odds and Evens free →