Invisible assistance
Also said as Hidden mechanics, Player-favouring tricks, Generous design
Help the game gives you without saying so: a hit area smaller than it looks, a health bar that drains more slowly near the end, a jump that works just after the ledge.
Near misses and last-second survivals are the best moments in a game, and they happen far more often when the odds are quietly bent. Players feel skilled, as long as they never catch you doing it.
Say it
“Make the last 20% of the health bar take half damage, and shrink the player's hit area to 60% of the sprite. Never show either. Then test whether anyone can tell.”
Where you’ve seen it
Developers shared these tricks in a thread started by designer Jennifer Scheurle in 2017. One she named herself: Assassin's Creed and Doom both count the last sliver of a health bar as more hit points than it looks, so you often feel you barely survived.
Not to be confused with assist mode
An assist mode is help you ask for and can see. Invisible assistance is on for everyone, and it only works if no one notices it.