Would anyone happen to know how subscription payments are handled if your game is on Steam? I know steam takes 30% of sales revenue…but how do subscriptions work? Are third party processors allowed (for example something like paypal or stripe)? If so does Valve expect you to pay them back the 30% of revenue you make?

What sparked my curiosity regarding this is that I had an idea for a simple strategy game that would be free to play, but for other features you would subscribe for some small monthly fee. Which got me thinking….if you're game is free to play…and you have an optional subscription…how would valve make money off of you…I can't imagine they'd just let that fly under the radar…?

I found this thread on steam which seems to go both ways with some people saying you can't and some people saying you can use outside payment methods…quite confusing.

And just to be clear, I'm not looking for some way to circumvent paying Valve…I don't even know if I'll pursue this idea…It just made me think and I thought it would be a nice discussion topic.

There is no simple answer. It gets complicated. Mostly it depends on details of your transactions, if they're considered in-game or out-of-game. If you're big enough (e.g. EA, Epic) you can also negotiate a specialized contract, but that's almost certainly not the case.

As your linked-to thread points out, with the standard contract any in-game transactions must use Valve's system. Depending on what you're doing you're fine to use it for out-of-game transactions, you could have your own website sell steam codes that you generate. That kind of system probably isn't worth the hassle for you, unless for some reason it is.

Read the contracts carefully, they have the details, and consider it relative to your proposed use. Be careful to not automatically interpret them in your own favor, but consider how lawyers and judges might interpret them if the situation is otherwise against you.

Not sure about this topic since I haven't developed any game. However, when my kid started to play different games, and he realized he loved coding, I found this platform where they have a long list of coding games for kids. Maybe you can try to contact them and see if they have something helpful for you. Moreover, I am sure Valve will find a way to make money from you since this industry has a lot of branches. If you are making money in any domain, there will be someone to make money out of you as well.