Reflect

TM43

Rest

TM45

Roar

Rest causes your Pokémon to fall asleep. This renders your Pokémon unable to use any other attacks for a total of 3 turns: the turn on which Rest is used, a turn on which it is fully asleep, and the next turn during which it wakes up.

Rest can only be used if your Pokémon is at less than full HP, even if it's affected by a status change. So if your Pokémon has been paralyzed, but has not been injured (eg, via Thunder Wave), it will be unable to clear the paralysis until it loses at least 1 Hit Point. It doesn't matter how the HP is lost, however.

Note that this attack will fail if the difference between the attacker's current HP and its maximum is 511, 255, or 0 (full health).

As an example, a Snorlax friend of mine has a maximum HP of 523 and was down to just 12 HP in battle. He tried to Rest off the damage, but Rest failed several times while his opponent was sleeping! (523 minus 12 is 511.) He lost the match and his trainer nearly had a stroke. Do the math and don't let this happen to you.

On the turn that Rest is used, all your Pokémon's HP are restored. Because Rest changes your Pokémon's status to SLP, it also removes any poison, burns, or paralyzation (assuming that this last effect did not prevent the use of Rest). Your Pokémon is protected from any further status changes while Resting. Rest does not remove or prevent confusion or Leech Seed, however.

Any statistic alterations, including Reflect and Light Screen, are retained while Resting.

Note that while each usage of Rest takes 3 full turns, only one PP is used during each nap.

While the number of turns slept has been rumored to be different in the Colosseum2 mode of Pokémon Yellow, this is not true. Just another unsubstantiated rumor...

Jigglypuff
Seel series
Snorlax

All Pokémon (except for Caterpie, Metapod, Weedle, Kakuna, Magikarp, and Ditto) can learn this TM.

This TM is unique and can only be obtained on the lower deck of the S.S. Anne.