The only way that the Batfamily really stays any kind of sane is that once in a while, they have a super competitive game night. When they do this, they quite literally only have one collective brain cell though.
Sometimes, it's a normal family game night with board games, but that's not enough excitement for a family of teenage vigilantes - Bruce usually taps out after before it gets too out of hand so he is exempt from any type of accountability - so they make some adjustments. It starts with just super competitive board game playing - which Bruce does stay for - and for games that might not be as competitive naturally like… go-fish or something, then they add extra rules to make it worse better.
Also because Bruce is a billionaire, and they all have the necessary skills for crafting even in a very different context, they can afford to make games more realistic like adding a real cardboard jail for monopoly (think I saw a fanart of this a while back and that's why I thought of this).
Because I'm convinced they're all just little nerds in some way or other, they've most definitely dressed up and played a real life D&D (as if they don't go out every night and fight real life bad guys) completed with homemade costumes - definitely not with certain pieces collected from Bruce's more… exotic Batman suits - and cardboard/wooden swords - Bruce doesn't participate because it gets ridiculous, but he has banned them from using their actual weapons - and for Jason, he of course, uses nerf guns. They usually only play how they're supposed to for the first half-hour tops before Jason just starts shooting all of them, Dick's dodging with flips while trying to use his sword as a lightsaber and block the bullets, Damian is stabbing/poking Tim with the pointy bit of his cardboard dagger, and Tim has somehow made a functioning bow and arrow using just paper - he's banned from using sticks because that could still hurt - and is attempting to shoot Damian point blank. Basically it's just cosplaying/costumed chaos.