Hit points (abbreviated as HP) are the value of damage a character in the Mother series can withstand before they are knocked unconscious. Playable characters can replenish this value by eating food or utilizing appropriate PSI (e.g. Lifeup, Refresh) to recover.
Unique to EarthBound and Mother 3, playable characters' hit points are represented by a rolling meter system not unlike an odometer. This means that if a character who has 75 HP is inflicted with 75 or more points of damage, their HP will not immediately drop to 0, giving players time to either flee, heal, or else defeat the remaining enemies if there is enough time. If a player is not healed or the fight is not ended by the time the player's HP drops to 0, that player will be rendered unconscious before the next character takes their move. In rare cases, players will survive a seemingly mortal blow with 1 HP. The chance of this happening is increased with a high Guts stat.
Initial gameplay features that creator Shigesato Itoi had in mind involved an unconventional hit points system of hit point boxes made like pachinko balls that would fall off the screen whenever a character was damaged. However, this was later changed to the odometer counter because the pachinko balls did not work very well when characters had large amounts of hit points.
The King Statue has the most HP for any single enemy or ally, having an insane 100 million.
The Lamp has the least HP for any single enemy or ally, having a meager 6 HP.
When it comes to allies, Ness has the highest base HP possible, coming in at 765. Flint comes second with 627. Poo is in third with 615. (From Level 99)
When it comes to allies, Paula has the lowest base HP possible, coming in at 315. Ana comes second with ~422. Jeff is in third with 465. (From Level 99)
- http://yomuka.wordpress.com/2009/06/21/weekly-famitsu-september-9-1994/ A translated interview with Shigesato Itoi, held by Weekly Famitsu on September 9, 1994