Health bar
Also said as Life bar, Ghost bar, Delayed health bar, Damage trail
A shape that shows how much damage you can still take. A common refinement is the ghost bar: when you are hit, the chunk you lost stays visible in a paler colour for a moment, then drains away.
A bar that simply jumps shorter tells you where you are, but not what just happened. The ghost shows the size of the hit, and it holds through a burst of small hits so you can see the whole of it.
Say it
“Add a ghost bar: after a hit, hold the lost chunk in white for half a second, restart that wait if another hit lands, then drain it over a quarter of a second.”
Where you’ve seen it
Elden Ring shows the chunk you just lost in a paler colour before it drains away. Hollow Knight skips the bar altogether and gives you masks, so you always know exactly how many more hits you can take.
Not to be confused with recoverable health
A ghost bar is only a display. Tekken 8's grey section looks similar but is real: it is health you can win back by attacking.