I have an old (Galaxy S1-class) phone running a custom ICS ROM. It has a pay-as-you-go mobile SIM without data.
I also have a bunch of kids with iPads that want to play Minecraft together. As far as I can tell, I can't get the iPad to make an ad-hoc wifi network on its own. If I had mobile data, I could turn on the Mobile Hotspot feature, connect all the iPads to the phone. I think if I did this now, though, my SIM would be charged for any stray Internet requests that are accidentally made.
Is there a simple way to do this?