e.g. A soldier shooting you faster on Veteran level but taking a bit to shoot you in Amateur.
In: Technology
Theoretically the computer program is capable of making invincible enemies with perfect aim and instant reaction times. To make the game easier, they just program the enemies to move slower and miss on purpose. If the enemies have special powers or movements (like dodging, taking cover) then the lower levels will just program to do that less. They may program them to move in ways that look more natural while still being easy.
My favorite example is the last level of call of duty world at war. On veteran mode they just make the bad guys throw like hundreds of grenades at you and never stop spawning.
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