A hard shell protects the Pokémon from critical hits.

shell-armor

Maximizes the number of times multistrike
moves hit.

skill-link

Protects the Pokémon from things like sand, hail,
and powder.

overcoat

status

Physical damage, controlled by Attack and Defense

physical

Special damage, controlled by Special Attack and Special Defense

special

One specific move.  How this move is chosen depends upon on the move being used.

specific-move

One other Pokémon on the field, selected by the trainer.  Stolen moves reuse the same target.

selected-pokemon-me-first

ally

The user's side of the field.  Affects the user and its ally (if any).

users-field

Either the user or its ally, selected by the trainer.

user-or-ally

The opposing side of the field.  Affects opposing Pokémon.

opponents-field

user

One opposing Pokémon, selected at random.

random-opponent

all-other-pokemon

One other Pokémon on the field, selected by the trainer.

selected-pokemon

all-opponents

entire-field

user-and-allies

all-pokemon

all-allies

fainting-pokemon

normal

fighting

flying

poison

ground

rock

ghost

steel

fire

water

grass

electric

psychic

dragon

dark

fairy

unknown

shadow

Its hard shell repels any kind of attack. It is
vulnerable only when its shell is open.

shellder

Once it slams its shell shut, it is impossible to
open, even by those with superior strength.

cloyster

generation-i

A physical attack in which the user charges and
slams into the target with its whole body.