Rock-Paper-Scissors is not my cup of tea, but I know others like it. I do realize there is a skill in being able to recognize and exploit non-random behavior in your opponent's choices.

Most of the time when this game is played, your opponent's choices will not be completely random and if not, it might be possible to take advantage of that, by outguessing them. And yes, your opponent might think they are playing randomly, but they most likely are not.

However, when playing R-P-S, if your opponent's choice IS indeed completely random, it is then impossible for you to exploit his/her moves. And then it's all a matter of luck again, for both players.

And yes, it's easy to indeed make a completely random choice. You can simply roll a die, for example. (If the result is a 1 or a 2, choose Rock. If a 3 or a 4, chose Paper. A 5 or a 6, choose Scissors.)

Another method, if a die is not handy, is to glance down and look at the second hand of your analog watch. (If the second hand is on the 1,4,7,10,13,16... etc., choose Rock. If the second hand is on the 2,5,8,11,14,17... etc., choose Paper. If the second hand is on the 3,6,9,12,15,18... etc., choose Scissors.)

When I was very young I can recall playing and enjoying the card game War. It might be played under different rules, but as we played the game, the game was 100% luck. As I got older, I discovered all luck games just weren't fun for me at all.