Psychic point
From EarthBound Wiki
Psychic points (abbreviated as PP) are the value of PSI a character in the Mother series (playable or opposing) can use in order to cast various PSI abilities. Playable characters can replenish this value by eating appropriate foods or utilizing appropriate Recover PSI. The only PSI that does not require a PP cost is PSI Magnet.
Unique to the 1995 video game EarthBound and the 2006 video game Mother 3 is that playable characters' psychic points are represented by a rolling meter not unlike an odometer. This means that PP used by an ability will not immediately be diminished. However this very rarely proves to be either advantageous or disadvantageous to the player, unlike with hit points, as even moves that drain large amounts of PP like PSI Rockin' Omega usually have animations long enough that the PP meter has finished rolling by the time the attack hits.
Concentration
Concentration is needed for an enemy or player character to use a PSI ability.
A few rare enemies in EarthBound (such as the Wetnosaur or the Mad Duck) can use an obscure attack that can disrupt one player character's concentration, making the PP-meter turn into an X. The player character will be unable to use PSI until concentration is regained.
Some enemies also suffer from poor concentration, such as the Mr. Molecule enemy, making their PSI moves fail randomly.
