Dynamic game difficulty balancing

Dynamic game difficulty balancing (DGDB), also known as dynamic difficulty adjustment (DDA), adaptive difficulty, or dynamic game balancing (DGB), is the process of automatically adjusting parameters, scenarios, and behaviors in a video game in real-time based on the player's ability. Its purpose is to prevent the player from becoming bored if the game is too easy or frustrated if it is too difficult.

Source: Wikipedia — Dynamic game difficulty balancing (CC BY-SA 4.0)