Only once

[NewbyZ]

How can I do that by doing damage to a mob this does something only once? And that only serves for that mob.

 

[ShaneBee]

What do you mean by "something only once"? What's "something". Please show an example of what you're trying to say.

 

[ShaneBee]

What do you mean by "something only once"? What's "something". Please show an example of what you're trying to say.

(Example)

on damage of spider:
    if name of victim contains "Example":
        if metadata value "Type" of victim is not set:
            set metadata value "Type" of victim to "Only1
             #Some hability"

When you hit him for the first time, he does something, when you hit him again he does not do it anymore
I have managed to do it with this, I hope you now understand what I mean, I suppose there will be a better way than this ....