Dice acts using sex dice. Dice may have numbers that do not form a counting sequence starting at one. One variation on the standard die is known as the "average" die. These are six-sided dice with sides numbered codice_3, which have the same arithmetic mean as a standard die (3.5 for a single die, 7 for a pair of dice), but have a narrower range of possible values (2 through 5 for one, 4 through 10 for a pair). They are used in some table-top wargames, where a narrower range of numbers is required. Other numbered variations include Sicherman dice and
Dice pool the Five Rings" and "7th Sea"). In dice pool systems it is common to add or subtract dice from the pool to represent different circumstances. Penalties may temporarily reduce the dice pool for one or more skills (for example, a leg wound may reduce the dice pool for actions such as running, climbing, and jumping), and are usually fixed numbers (i.e. the leg wound may reduce a pool by two dice). Bonuses may temporarily increase dice pools, and usually represent beneficial circumstances (e.g. a character may have a powerful computer to aid her in a database search) or some special