Building a card tower is challenging, but it can also be a good way for kids to work with their fine motor skills and just plain have fun. One deck of cards is plenty for most purposes, but if you really get into it all you need is more decks!
Building a card tower takes a lot of patience, especially if a family pet or sibling comes and accidentally knocks the whole thing down just as you’re getting things going or are almost done. You want to pick the place you start working very carefully.
If you’ve never built a card tower, there are plenty of tips online. Just do a search and you’ll soon have a pretty good idea for how to get started.