Double Kick (move)/Effect

Generation I
Double Kick inflicts damage, hitting the target twice per use. Although only the first strike can be a critical hit, the second one will deal the same amount of damage.

Double Kick will end immediately if the first strike breaks a. and will only acknowledge the second strike of this move.

Generation II
Each strike now does damage independently, consequently enabling either of them to be critical.

If the user is holding a King's Rock, the final strike has a chance to cause the opponent to.

Generations and
Double Kick will now hit again if the first strike breaks a substitute.

If the target has an Ability that activates upon contact, each strike counts individually, enabling the Ability to activate twice.

If the user is holding a King's Rock or Razor Fang, each consecutive hit has an equal chance to cause the opponent to.

Generation V onwards
If the first strike activates the target's Focus Sash, Focus Band, or, the second one will cause the defending Pokémon to faint. A Focus Band can still activate again to prevent fainting, but this chance is independent of the previous one.

If the target has, each strike will activate it.

If the target is holding a Rocky Helmet, the user is damaged for each strike.