Fist

In Assassin's Creed the fists are the weakest form of fighting available to the player. Guards will not intervene with a fistfight, unless the player is attacking a guard. However, if the player draws a weapon they will attack.

Assassin's Creed

the assasins fists are a useless form of attack the enemy will puncture your heart and chop off your fists try and get a sword. 

Assassin's Creed II

In Assassin's Creed II, the main character Ezio is more skilled in a fistfight. He can perform combos, as well as being able to counter other fistfighters. He may also Disarm those with weapons and use them against opponents, if he has learned the Disarm skill. The special attack while unarmed is to lean down and sweep some sand into the opponent's eyes, opening the weaker enemies to an instant kill. Similarly, if your opponent has sufficiently low health, it is possible to perform an instant kill if you can get behind them.

Fists also becomes a more viable weapon when the Metal Cestus, a hard steel handguard that strengthens the attack of the fists, becomes available for purchase.

You can earn yourself the achievement/trophy, Messer Sandman, which is worth 10g or a Bronze trophy, by using the sand throwing move on 4 guards at once.

Stats

Without the Metal Cestus upgrade, Ezio's fists have 1 damage, 5 speed, and 1 counter. The Metal Cestus boosts the damage stat to 3.