Double Team (かげぶんしん Kage Bunshin, Shadow Clone) is Lucario's down special move. It is a counterattack move. When used, Lucario enters a defensive tai chi-like stance. If it is attacked during this stance, it will teleport, then strike with a sliding kick from the left or right (depending on the direction the analog stick is held in) for moderate damage and surprisingly high knockback, which is even greater when Lucario has taken damage. If Lucario successfully counters with Double Team near an edge, it may teleport above the ledge and fall downwards as it unsuccessfully attacks, making recovery difficult. Double Team has a longer length than Marth's and Ike's Counter. It is notably different in that it does not change power depending on the countered move; rather, it does a constant attack no matter what moves it counters. One of the most interesting features of Double Team is its damageable area elimination. If Lucario is hit during a Double Team and goes into the counter strike, Lucario will not have a damageable area until it completes the counter attack. Lucario can't be hit, grabbed, or even caught in a Final Smash by anyone or anything. Double Team also reduces Lucario's falling speed for a minor duration. This move is rather easy to dodge, as it is possible to air dodge or shield the attack when Lucario disappears. It also has some invincibility frames to it when activated. Being an Aura based attack, it does 7% at damage below 20% and at 170% or higher it deals 15%.
Note that Lucario actually strikes the location around where it was hit, just like Counter does. If Double Team is used on a ranged attack or an attack that causes its user to move quickly (Spin Dash, Rollout, etc.), Lucario will most likely miss with his counter attack.
Double Team is rather useful in Boss Battles mode to dodge boss attacks. While it isn't guaranteed to hit the boss (and even then, it doesn't deal much damage), it is a quicker way to dodge than a roll, short hopped air dodge, or just running away, and it has longer duration than a sidestep.
In the Pokémon games, Double Team is a status Normal-type move introduced in Generation I, which raises evasion by one stage, making attacks miss more often, and can be stacked for even larger evasion boosts, although in Pokémon, it is in no way a "counter-attack". It is generally banned in competitive play for its reliance on luck and its difficulty to counter effectively when paired with Baton Pass, making Double Team very infamous among players. The animation in Brawl is similar to the animation in the Pokémon games (notably ones like Pokémon Battle Revolution or Pokémon Colosseum). Interestingly, Lucario can't learn Double Team naturally and it requires TM32. It is a move that can be learned by any Pokémon that can learn TMs.