My ex used to do this when he couldn't decide what to order at restaurants. He'd make a list of the things he was considering, ask someone at the table to pick a number between, say 2000 and 5000, and mod that number by however many choices were on the list, then order that thing.
I would only use these kind of methods for low-impact decisions, e.g. "what should we have for dinner tonight," and "which movie do you want to see?" In some cases, it can be a valid way to remove the pressure of making a decision, when you know the outcome doesn't matter either way.