Best of 3 vs Best of 5

Best of 1 is a coin toss with extra branding. Best of 3 is the default for a reason. Best of 5 is for when the loser will complain that best of 3 was luck.

What the numbers mean

Best of 3 ends at 2 round wins. Best of 5 ends at 3. Draws do not move the win clock, so a 'best of 3' can last five throws if people keep tying.

Luck vs information

Each extra round does two jobs: it averages out flukes, and it gives you a longer look at the other person's habits. If you are playing a stranger you will never see again, best of 3 is enough. If you are settling something that will be quoted later, best of 5 is cheaper than an argument.

Infinite

Infinite mode is for messing around. There is no match winner. Use it when the point is the conversation, not the scoreboard. Set the format on the Rock Paper Scissors game page before you invite someone — both of you should know what you are playing for.