The Item Switch is a menu in the Super Smash Bros. series where players can select what items they want or do not want to appear in matches, as well as the overall frequency of their spawning. Players cannot, however, alter how often certain items appear compared to others (for example, Heart Containers will always be one of the rarer items).
Super Smash Bros. is the only game in which players must first unlock the Item Switch, which they can do by playing 100 Versus Mode matches. Players can then select which items they want to appear in a match and how often they appear, from very low to very high. Green Shells and Red Shells cannot be switched individually; they are both covered under the item "Shell".
In Super Smash Bros. Melee, the Item Switch is available by default. As in Super Smash Bros., players can select which items they do or do not want to appear in a match and how often they appear, from very low to very high. However, they cannot turn off the container items such as Capsules, Barrels, and Crates. Instead, they must set the item frequency to none for these items to not appear.
The Item Switch returns once again in Super Smash Bros. Brawl. This time, it has an on/off switch for instantly turning all items off or on, and players can turn off container items without having to set the item frequency to none. However, players can no longer put items on very low or very high. Instead, they can only put them on None, Low, Medium, or High. Also, collectible items such as stickers cannot be disabled without setting the item frequency to None. In addition, the game provides a short description of the currently highlighted item at the bottom of the screen.
The Item Switch can be used again in Super Smash Bros. for Nintendo 3DS, and almost acts like the Brawl version. However, there is no option to change the frequency of the items. In Super Smash Bros. for Wii U, Brawl's item frequency options return. Also, as with Brawl, the game provides a short description for each item.
In Ultimate, each ruleset has its own unique Item Switch, allowing players to enable and disable specific item spawns within separate rulesets. While editing a ruleset, the Item Switch can be accessed under Items. Returning from both Brawl and for Wii U are the ability to change item spawn frequencies and short descriptions of each item's functionality.