I have not modded a single game in my life, but I really, really want to start. I'm a 3D animator (make no money from this, just a serious hobby) and a budding Object Orientated programmer (make all my money from my own web applications, I'm not a millionaire but I live comfortably and have bags of time on my hands) so I feel like I will be able to make some incredible mods.

Fallout is my favourite game series of all time, has a vibrant modding community, its open-world style means the sky's the limit (and occasionally further!), there are excellent modding tools available (such as the GECK), and Bethesda has an excellent attitude towards licencing (unlike those nazis over at EA), so I'm one-hundred percent sure that's what I want to mod.

However I have no idea what modding a game is like, and while the only way to find this out is by modding, what I'd really like to know is how do I determine when is the right time to mod? My heart wants to download the GECK (the fallout editor) right now and get stuck in, but I'm being sensible and writing this question.

The last fallout game (New Vegas) is nearly half a decade old (2010) and Fallout 4 is lurking in the future somewhere. I want to dive in modding new vegas, but where will I be when fallout 4 comes out? Will there be only a slight learning curve and then all the skills I've learned will be utilized to start modding really quickly in Fallout 4?

Or, in between games, are modders simply left in purgatory regarding future releases? Could I become a Fallout 3/NV mod ninja, and then have to learn everything again come Fallout 4? Or do companies such as Bethesda make an active effort to keep everything consistent?

I feel 3D engines are like web frameworks such as Zend and Rails. Basically, I've put all my eggs in Rails and have never looked back. I'm sure that as the web changes, Rails will change with it. I spend every moment of my professional life with Rails as I'm confident it will never die and I will be able to build on my existing skills until I retire. This attitude means I can really throw myself at projects, go the extra mile and learn new skills. However, will I not be able to do this with modding? Will there always be lurking doubt that come the next game, everything I've learned will be useless? Will every new game hit me with a learning curve?

Also (and this would me awesome if true but I kind of doubt it), are moden games similar enough that if I'm a Fallout ninja, the learning curve wouldn't be too crazy if I then wanted to mod Crysis or Portal or even a non-fps like Civ5?