First roll D100 to determine a change then roll D100 again to determine success or failure. Isn't that truly a random roll?
Roll D100, get a result of 53 what means that there is 53% change of [what ever is in question]. Then roll D100 again to see what happens based on that randomly determined % change.
Isn't that wonderful? Okay, that is totally unnecessary and really, it is too random for anything more important than what change the random flower is blue or red. In my opinion.
But still, I remember when being a kid and GMing I did use that double-random roll. For example if characters were sneaking and I had to determine does a guard detect them -that game didn't have rules for sneaking- I first rolled the percentile for guard's detection and then re-rolled against that first rolled to see were players detected by the guard.
Yes, those were very simple times. But still, back then there was this rule of thumb always present:
If you don't remember how the rules work, adapt."
And that was adapting. Instead of figuring out what ability against what should be used in what manner from really narrow list without rules was determined more simple way. Roll - roll - done.
It is not realistic, but it was fun and easy. Naturally later on solving these small problems of rules and game situations developed a lot and it was easy to create hastely rules that were similar enough with the core game.
But still, I remember telling players:
"You see the guard up there tower. He has a spear and he's looking at in various directions." Players agree to sneak. Behind my GM screen I make a secret roll and I see players' nervous looks. They wait for the result, but then I make a second secret roll and after that tell the result.
Imagine. Secret rolls in high tension situations were bad enough. But double-secret-rolls? Killers! Same I used sometimes when rolling for players. Player doing something with really uncertain result. Sometimes GM makes rolls in these situations as player don't always know what stats to use. But use a double roll here? It's a killer.
Naturally that double roll can be a game killer and should be used extra rarely with caution. It is random roll. Really random roll. Unless you absolutely want to make a random roll, do it. If you are unsure how to response and what happens, I am not sure if it's that good. Like does inn keeper know something important? Why bother. Just determine the % he could know with a little bit imagination where this % comes (inn keepers know the rumors, target easy to point out from a crowd, well known rumor etc. affect the %).
But sometimes, do a random random roll. Just for the fun of rolling dice.