Anti cheat?

Question

I was wondering if there is a way to create a logic that denies the variable to be modified from outside of the program like cheat engine in c#? Doesn't matter how many times i tried to create algorithm, it can't prevent the variable from beeing modified. I'm trying to make the variable protected from outside attacker without using any variable modifierlike protected, or private or constant.. But the actual way / logic that plays in the role. Is it possible? I just couldn't find how it works.

Answer 1

Apply a checksum. This will corrupt the file if it's altered and the checksum doesn't add up.

Answer 2

The server should check whether a number is possible. For example, is AMMO smaller than MAX AMMO? Did AMMO change before RELOADING was true for 1.5 seconds? If so, cancel the reload.