Wild Kick

Flip a coin. If tails, this attack does nothing.

Riolu

Cosmo Holo Great Encounters Blisters (March 2008)

Flip a coin. If heads, this attack does 10 damage plus 10 more damage.

Cracked Ice Reverse Holo Trainer's Challenge Box (end of October 2009)

Flip 2 coins. This attack does 10 damage times the number of heads.

Riolu can't attack during your next turn.

Flip 2 coins. This attack does 20 damage times the number of heads.

Gold Snowflake Stamp Pokémon Countdown Calendar Exclusive

Flip a coin. If heads, this attack does 20 more damage.

Flip a coin. If heads, prevent all effects of attacks, including damage, done to this Pokémon during your opponent's next turn.

This attack's damage isn't affected by Resistance.

Flip a coin. If heads, this attack does 20 damage plus 10 more damage.

Staff Comic-Con International: San Diego 2009

This Pokémon also does 20 damage to itself.

Switch this Pokémon with 1 of your Benched Pokémon.