There are lots of systems around, many aimed at simpler and more story-focused play than D&D. Downside is they usually have fewer resources for DMs so you'll be

There are lots of systems around, many aimed at simpler and more story-focused play than D&D. Downside is they usually have fewer resources for DMs so you'll be making your own campaigns, designing your own encounters, and so on, more often, even if you'd rather not. Though 5e and Pathfinder 2.0 streamline things quite a bit and do a better job of putting class flavor into the system itself and working at keeping the combat system more fluid and engaging for the whole table. There's been an explosion of simple RPG systems focused on younger players, so if the kids you're targeting might get lost in or bored by the rules of even a modernized D&D-alike, there are lots of specialized kid-friendly options. Example of one with fairly high production values if you want a take-out-of-the-box-and-play experience, targeting really young kids: http://www.nothankyouevil.com http://www.nothankyouevil.com I've not played it but it seems pretty well-regarded and I've seen it mentioned a lot. Just an example, there are tons, many of them of the self-published PDF-book-and-character-sheets variety.