Zocchihedron is the trademark

Trademark

A trademark, trade mark, or trade-mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or...

 of a 100-sided die

Dice

A die is a small throwable object with multiple resting positions, used for generating random numbers...

 invented by Lou Zocchi

Lou Zocchi

Louis Zocchi, Sergeant, USAF , is a gaming hobbyist, former game distributor and publisher, and maker and seller of polyhedral game dice....

, which debuted in 1985. Rather than being a polyhedron

Polyhedron

In elementary geometry a polyhedron is a geometric solid in three dimensions with flat faces and straight edges...

, it is more like a ball with 100 flattened planes. It is sometimes called "Zocchi's Golfball".

Zocchihedra are designed to handle percentage rolls in game

Game

A game is structured playing, usually undertaken for enjoyment and sometimes used as an educational tool. Games are distinct from work, which is usually carried out for remuneration, and from art, which is more often an expression of aesthetic or ideological elements...

s, particularly in role-playing game

Role-playing game

A role-playing game is a game in which players assume the roles of characters in a fictional setting. Players take responsibility for acting out these roles within a narrative, either through literal acting, or through a process of structured decision-making or character development...

s.

History

It took three years for Zocchi to design his dice, and three more years to get it into production. Zocchi discovered that the dice would perform best at a depth of 13.85 mm. Since its introduction Zocchi has improved the design of the Zocchihedron, filling it with teardrop-shaped free-falling weights to make it settle more swiftly when rolled.

The Zocchihedron II is a further improved model, and has another filler.

Probability distribution of rolls

A test published in White Dwarf magazine concluded that the frequency distribution of the Zocchihedron was substantially uneven. Jason Mills performed 5,164 rolls and found that results more than 93 or less than 8 are significantly rarer than middling results. Mills attributed this to the placement of the extreme numbers near the poles of the zocchihedron, where they are closer together. Numbers near the equator are more widely spaced.

Later versions of the Zocchihedron have been designed with a different pattern of number distribution, resulting in more even results overall.

Patents

The aesthetic appearance of the Zocchihedron was protected by United States design patent

Design patent

In the United States, a design patent is a patent granted on the ornamental design of a functional item. Design patents are a type of industrial design right. Ornamental designs of jewelry, furniture, beverage containers and computer icons are examples of objects that are covered by design...

 D303,553, which expired on 19 September 2003. There was never a utility patent

Patent

A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....

for the original Zocchihedron, although United States patent 6,926,276 may protect the braking mechanism of the Zocchihedron II. That patent will expire on 9 August 2025 and applies only to 100-sided dice containing "multi sized and irregularly shaped particles."