Allow account creation with just a Username (no password)?

I’ve made a little trivia challenge app that’s really just meant for personal use. I’d like to make it so that a new user can “create and account” with just a username (basically a team name), and not require a password.

This is just so I can keep track of scores in a game really. But I want to make sure I’m using the build in accounts features, as that’s how I’ve written my code already. This is for a family activity, and as much as I love 'em, my family isn’t that technologically savvy, so making it super easy is important.

To be clear my question is, how do I allow account creation in meteor with just a username (no email, no password required)?