From Bulbapedia, the community-driven Pokémon encyclopedia.
Recoil is damage a Pokémon can receive upon using a damaging move. Life Orb causes damage similar to recoil when its holder uses a damaging attacking move; however, this damage is relative to the holder's max HP, not the damage dealt, and is not considered recoil by game mechanics.
The moves Jump Kick and High Jump Kick have a similar mechanic called crash damage. The crash damage is only dealt if the move misses, rather than upon inflicting damage to an opposing Pokémon.
In Pokémon Stadium, if a recoil move knocks out the opponent, then the user will not take recoil damage.
The Ability Magic Guard prevents most forms of indirect damage, including both recoil and the damage taken from Life Orb. The Ability Rock Head prevents only recoil damage; it does not prevent damage taken from Life Orb. Neither Ability prevents recoil from Struggle, Shadow Rush or Shadow End.
The Ability Reckless increases the power of moves with recoil by 20%, except Struggle. Reckless does not increase the amount of recoil taken directly, but the user will also take 20% more recoil than normal because of the damage increase. Reckless does not increase the bonus or damage taken from Life Orb.
Since recoil is a primary effect, it is not negated by Sheer Force. However, since the damage taken from Life Orb is a secondary effect that activates after the attack is executed, Sheer Force will prevent it.
Moves with recoil damage
Moves with crash damage
In the anime
Infernape damaged by recoil
A number of times in the anime, recoil has been noted. The most notable is Pikachu's Volt Tackle. Brock has stated many times that Volt Tackle causes recoil and is very risky.
Ash's Staraptor and Reggie's Staraptor both know Brave Bird, which was stated to do recoil damage, making it a very risky move. The same goes for Flint's Infernape and Ash's Infernape, who both know Flare Blitz, and Roark's Rampardos, who knows Head Smash.
Take Down is referred to as a risky move numerous times in the anime, along with Double-Edge. However, in some cases, such as The Battle of the Badge, where Ash's Pidgeotto used Double-Edge, it took no recoil damage. However, a case like that is mostly only in the earlier series.
Crash damage has been featured in the anime as well. When Gilbert's Hitmonlee failed to hit Pikachu with High Jump Kick in Saved by the Beldum, it only got hurt itself. Another such case was in Wheel of Frontier, when Greta's Medicham was hurt when its High Jump Kick failed to hit Snorlax. Ash's Scraggy has also got hurt a couple of times as his High Jump Kick has crashed. Korrina's Mienfoo took crash damage after Ash's Hawlucha dodged its High Jump Kick in Showdown at the Shalour Gym!.