Morra (or La Morra) is an ancient Roman game of chance still played in some areas of the world. The Romans designated the game micare digitis, "to flash with fingers." It is similiar to the game Rock, Paper, Scissors but with more choices.

Object of the game:

The object is to guess the total number of fingers extended by yourself and your opponent.

Game Play:

First the number of rounds a person must win in order to win the match is determined, often 5 or 10 rounds are played.

The two players face each other

At the count of three both players simultaneously unclench their right hand with their own choice of fingers extended and call out a number from 0 to ten.

If one player guesses the correct number of fingers extended they win that round, if both players guess the correct number then it's a draw and no one wins the round. A tie means no score.

Notes:

This game is very easy to learn and play and has often been used as a gambling game. It's a tradition among many in Italy, being passed down through the generations, as a part of their heritage. It has also been featured in poems and art work including the Giuseppe Geioacchino Belli sonnet "L'ADUCAZZIONE" (posted below in English).

EDUCATION

My son, never do wrong to your daddy,
Take care, don't let yourself be subdued.
If someone ever hits you,
Straight away you hit him twice.

And if any other bastard
Tries to lecture you,
Tell him: "I don't care a damn about these reasons:
Everyone mind his own business".

When you bet a jug of wine playing morra,
Drink, my son; and don't let these fools
Have a single drop.

To be a cristian is another good thing:
For this reason always keep in you pocket
A sharpened knife and a rosary.

Rome, September 14, 1830
--Project Gutenberg

Morra is also featured in books such as UARDA By George Ebers:
Under a wide-spreading sycamore a vendor of eatables, spirituous drinks, and acids for cooling the water, had set up his stall, and close to him, a crowd of boatmen, and drivers shouted and disputed as they passed the time in eager games of morra.
(In Latin "micare digitis." A game still constantly played in the south of Europe, and frequently represented by the Egyptians. The games depicted in the monuments are collected by Minutoli, in the Leipziger Illustrirte Zeitung, 1852.)
--project gutenberg