Items

Most common items
Assault Vest = Sp.Def is 1.5x, but you can only select damaging moves

Air Balloon = makesyou immune to Ground-type attacks until you're hit

Big Root = you gain 1.3x HP from draining moves, Aqua Ring, Ingrain, and Leech Seed

Black Belt = your Fighting-type attacks do 1.2x damage

Black Sludge = heals 1/16th of your max HP if you're a poison type at the end of every turn, otherwise you lose 1/8th

Chesto Berry = wakes you up once

Choice Band = Attack is 1.5x, but you are locked into the first move you use

Choice Scarf = Speed is 1.5x, but you are locked into the first move you use

Choice Specs = Sp.Atk is 1.5x, but you are locked into the first move you use

Damp Rock = makes Rain Dance last 8 turns

Eviolite = makes a not fully evolved Pokémon's Defense and Sp.Def 1.5x

Eject Button = when you're hit and survive, switches your Pokémon out to a chosen ally once

Flame Orb = tries to burn the holder at the end of every turn (FLING TO BURN)

Focus Sash = when at full HP, prevents you from being OHKO'd

Heat Rock = makes Sunny Day last 8 turns

Icy Rock = makes Hail last 8 turns

King's Rock = gives 10% flinch chance to moves that don't already have a chance to flinch (FLING TO FLINCH)

Leftovers = restores 1/16 of your HP at the end of every turn

Light Clay = makes Reflect and Light Screen last 8 turns

Life Orb = your attacks do 1.3x damage, but you use 10% of your max HP after the attack

Lum Berry = heals confusion or a major status condition once

Mental Herb = cures Attract, Disable, Encore, Heal Block, Taunt, Torment once

Muscle Band = physical attacks have 1.1x power

Power Herb = completes a two-turn move, except Sky Drop, in a single turn once

Red Card = if you survive a hit, the Pokémon that hit you has to switch to a random ally

Rocky Helmet = when hit by a contact move, the attacker loses 1/6th of its max HP

Safety Goggles = protects you from powder moves, Hail, and Sandstorm

Sitrus Berry = Restores 25% max HP when you''ve less than 50% max HP once

Scope Lens = raises your critical hit ratio by 1

Shed Shell = allows you to switch out, even when you're trapped

Shell Bell = you gain 1/8th of the damage in HP dealt to the other Pokémon

Smooth Rock = makes Sandstorm last 8 turns

Toxic Orb = badly poisons whoever holds it at the end of every turn (FLING TO POISON)

Weakness Policy = raises Attack and Sp.Atk by 2 stages when hit super-effectively once

White Herb = when one stat is lower than 0, restores them back to 0 once

Wise Glasses = special attacks have 1.1x power

Pokémon-Specific Items
Blue Orb = triggers Kyogre's Primal Reversion

Deep Sea Scale = doubles Clamperl's Sp. Def

Deep Sea Tooth = doubles Clamper's Sp.Atk

Griseous orb = Giratina's Ghost- and Dragon-type attacks have 1.2x power

Light Ball = doubles Pikachu's Attack and Sp. Atk

Lucky Punch = raises Chansey's critical hit ratio by 2 stages

Lustrous orb = Palkia's Water- and Dragon-type attacks have 1.2x power

Metal Powder = doubles an untransformed Ditto's Defence

Quick Powder = doubles an untransformed Ditto's Speed

Red Orb = triggers Groudon's Primal Reversion

Soul Dew = makes Latias's or Latios's Sp.Atk and Sp.Def 1.5x higher

Stick = raises Farfetch'd's critical hit ratio by 2 stages

Thick Club = doubles Cubone's or Marowak's Attack