1. Screens off. Sorry, guys, but if you stay indoors today you won't be on your devices. Or the Television. Or Netlfix, Wii or DS. I started a two-hour online anti-virus checkup on my son's laptop to tie that up, too, so he can't retreat to his room to do "school work", a euphemism for watch YouTube videos.
2. Indoor chore list. If you must be inside, boys, I've got a lot things that need done. Laundry. Closet organizing. Toilets. And if you start fighting out there so that I have to call you in and break it up, the chores will be inside waiting.
3. Join them. A snow day is a great chance for my kids to get the unstructured, outdoor free play time with their peers that they otherwise get so little of, and so I like to stay out of it and let them be with their neighbors and each other. On the other hand, I want to be a role model and show them that I, too, like to be outside on a snowy day. So later on I will be out chucking a snowball or two. Maybe building a snow shelter. But by that time, they won't need me to be out there. When I called them in for a lunch a few minutes ago they were making plans to sled after they eat. So I will probably end up shoveling the driveway, alone.
And that is my plan. Once outside, they almost always want to stay.