Common Held Items
A list of common held items in competitive Pokémon.
 Offensive Pokémon Items
Increases move power by 30%, but costs 10% of the user's HP with each successful attack.
Life Orb is one of the most common attack boosting items in competitive Pokémon. The 30% boost helps many Pokémon get key OHKOs and 2HKOs. The Pokémon is also free to choose their moves, unlike Choice Items. The boost is applied to every attacking move using the normal damage formula.
The 10% recoil can be an issue for some Pokémon though. The recoil can leave them vulnerable to priority moves. Also, with possible damage from entry hazards and weather, the Pokémon will lose HP very quickly.
Increases attack by 50%, but locks the user into a single move.
Choice Band is best suited for physical sweepers who can hit hard with one move. The extra power is a bonus, however, being locked into a single move (especially one that can be resisted easily) can allow the opponent to set up if they can take advantage of the situation.
Increases special attack by 50%, but locks the user into a single move.
Choice Specs are best suited for special sweepers who can hit hard with one move. It faces the same problems as Choice Band though.
Increases speed by 50%, but locks the user into a single move.
Choice Scarf is a useful item for attackers who need extra speed to sweep or revenge killers. However, no extra attacking power is gained, and the problems of being locked into a single move still exist.
Increases the power of super effective moves by 20%.
Expert Belt is a good choice for Pokémon that can get very good super effective coverage with 4 moves. While it's not as powerful as Life Orb, it doesn't have the recoil. Generally, it is used to make an opponent think the holder is using a Choice item, which can earn some surprise kills.
 Defensive Pokémon Items
Restores 1/16 of the holder's max HP at the end of each turn.
A Leftovers Number is a number that is divisible by 16, allowing Leftovers to work to its full effect.
Increases the Defense and Special Defense of a NFE (not fully evolved) Pokémon by 50%.
Eviolite is useful for NFE Pokémon as it allows them to take more hits. Some Pokémon with Eviolite have more bulk than their fully evolved forms. However, the recovery from Leftovers is not available, and many Eviolite Pokémon lack the power to hit their opponents for enough damage.
Gives a Pokémon immunity to Ground-type attacks and grounded entry hazards until the Pokémon is hit with a direct attack, which will remove the Air Balloon.
The Air Balloon is obviously best for Pokémon that fear Ground attacks. Heatran is one such beneficiary, and can even use it to check the Ground-types it would normally fear, such as Excadrill. Unfortunately, as the Air Balloon can be broken by any attack that the target is not immune to, it can often prove unreliable, and is also not considered a valid argument in Suspect Discussions.
When the holder is at full HP, moves that would OHKO it leave it with 1 HP instead. The Focus Sash is then used up. If the user is not at full HP, the item will not be used.
The Focus Sash is an odd mix of offense and defense. On one hand, the item has a defensive effect, allowing a Pokémon to survive a little longer. On the other, defensive Pokémon hardly ever have need for it; users of Focus Sash tend to be offensive Pokémon who either need a turn to set up or just appreciate an extra turn. However, with the proliferation of entry hazards, damaging weather, and priority, the Focus Sash has become much less reliable and is not commonly used.
A broken sash is either a Focus Sash that has been used up or otherwise negated due to the user not being at full HP. If a holder of Focus Sash is damaged, but the Sash is not used up, the Sash can be used up later if the user somehow gets back to 100% HP. Fake Out is the best move that put off the effect of the focus sash. Plus, the opponent flinches.
Lum Berry is a good option to avoid status problems for one turn. It is most commonly seen on lead Pokémon to stop status setting leads, or it can be used on a late game sweeper to avoid being harmed by status.
Heals Sleep. Consumed after one use.
Although at first glance Lum is better than Chesto by far, Chesto does have one advantage--it won't be as easily absorbed as early. This allows Rest+setup users to instantly heal off any status and damage after setting up without having to deal with the 2 turns of Sleep, which Lum cannot do if the opponent can inflict status conditions.