Morality system
Also said as Karma, Good and evil meter, Paragon and Renegade
The game scores your actions on a good-and-evil scale, then changes how the world treats you. It turns ethics into a number, and players treat numbers as things to win.
It is cheap to build and gives clear feedback, but once a reward sits at the end of the bar, players stop asking what is right and start asking what the bar wants.
Say it
“Drop the karma bar. Track what they did as specific flags, so helping a beggar does not undo a murder, and let the people involved react to the thing they saw.”
Where you’ve seen it
In Mass Effect, high Paragon or Renegade scores open conversation options, which encourages you to pick one colour and stay with it. BioShock's Little Sisters are a simpler moral test whose result decides the ending.
Not to be confused with reputation
Morality scores you against the game's idea of right and wrong. Reputation is what particular people think of you, and two groups can disagree about the same act.