The Careless Sash is an item in the Pokémon games. It is a variation of the Focus Sash. This item is a hypothetical item, meaning it has yet to appear in any officially released Pokémon games.
Effect edit
If the holder of the Careless Sash is at full HP prior to taking damage, the item allows the holder to survive an attack that would otherwise knock it out from full health. If an attack would cause the holder to faint, the holder will instead hang on with an amount of HP equal to the number of careless mistakes the human player of the game made during the previous X seconds, where X is the total HP of the affected Pokémon.
For example, suppose that you, the human user of the Nintendo console you are using to play the game, made 6 careless mistakes during the last 3 days (259,200 seconds). If your Pokémon has 259,200 HP and is at full health, no amount of damage will cause your Pokémon to faint from full health; instead, any attack that would normally KO it will instead leave it at 6 HP. In the Pokémon games, the HP bar displays two numbers separated by a slash, with the number on the right being the Pokémon’s total HP and the number on the left being the Pokémon’s current HP, so in our example, this will be denoted as “6/259200”. By default, a Pokémon is at full HP so the two numbers are the same. For example, Pokémon that hatch from eggs are born with full HP, and most Pokémon have eleven or twelve hit points at level one, so this is denoted “11/11” or “12/12”. These look like the dates November 11 and December 12, but in this context, the expressions are being used as fractions, not dates. The fraction 6/17 has a value of 6/17 = 0.35294117… so a Pokémon with a total HP of 17 that currently has six hit points remaining has 35.294% of its total HP.
The Careless Sash becomes increasingly more effective during time intervals that are clumsier than the average interval of like duration, as the floor number below which the Pokémon’s HP cannot fall is directly equal to the number of careless mistake seconds in the interval. However, in practice, the difference between 6 hit points and 10 hit points is negligible on the scale of thousands or millions, so trying to have clumsy intervals of time just so you can power up the item is highly discouraged.