When is a update to a mod necessary ?

[Thretcha]

(I assume) Since mods are built without any minecraft or forge code, do I only have to update my mod when newer versions break my code?

Or do I have to release a new version with every forge update, or just with every minecraft update ?

I haven't added dependencies for a specific forge or minecraft version in my code.

[Draco18s]

Usually every Minecraft update.

[jabelar]

Well, it is very unlikely for a mod to not require an update, but it is possible. 

 

An easy way to prove you do need to update is to copy your mod source into a new folder, update the build.gradle to download the latest Forge version, create the updated workspace and IDE project and open in your IDE. If you see a bunch of errors then you need to update!

 

Based on my experience, every Minecraft update requires source code update. Even little things like changing the packages, to fundamental things like moving to the block state system.

 

But a very very simple mod, where the classes it references haven't moved, been renamed (including names of methods) and none of the method parameters have been changed, then you  might get away with it.

 

I have also found times where I've had to update during same MC version as Forge usually has an inital period of development for each MC version where things can change a bit. But I think they try as hard as they can not to break things within the same MC version, so it is rare.