Question for devs

From a coding perspective, how do you make everything future proofed? Like this'll be hard to explain but I'll give an example:

for lucians dash:

if notstunned and >>>notgrounded<<< and etc etc

like how would you easily incorporate a new debuff like grounded into the game so easy? do you go through every mobility spells code and change the conditions for when it would work? sorry if this is too vague but I've been wondering about this for a while