HP

From Fire Emblem Wiki

HP, or Hit Points, are very important and play a very large role in the Fire Emblem universe. The term HP is used in several other video games and usually plays the same role.

[edit] Role

All characters have HP. Hits will remove certain numbers of HP from the unit being hit. Certain weapons like the dark magic book Nosferatu and the dark magic infused Runesword, among others, do not only remove HP from the hit unit, but bring them to the user of this weapon who then receives the same number of HP.

[edit] HP Recovery

Recovery Items always have the same general effect. This being to recover lost HP. Hence the name. Many staves also recover lost HP. Some buildings and structures(i.e:fortresses, thrones, gates...etc) may recover small amounts of the HP of the unit standing upon it if the unit finishes his turn there.

Some units, such Fighter and Knight tend to have more HP than other units, like Mage or Thief.