Playing the scenerios without the ruleset ?

Hi !

Is it possible to use the CoC scenarios (The shadow over providence per exemple) without buying the Ruleset ? We got the quick start rules and we want to play trough Fantasy grounds (COVID) to try CoC while we take a little pause from D&D. The Ruleset already cost a lot, so we would like to just try one of the aventures

Not really, not easily anyways. There are extensions that would allow you to open the scenario in another ruleset but they don't work really well I find because alot of it isn't recognized by the ruleset you're in. Probably the easiest way to try it out would be to go to the Looking for Group here on the forums, on the Discord server and even the Facebook page for FG and ask if there's a CoC Keeper that would be willing to take a group and introduce them to the game. You could even just use FG as the die roller and run it from the pdf.

Welcome CaptainTiefling

You can load most Call of Cthulhu mechanics in MoreCore and use Universal Modules extension to load up the module.
Any pregens and monsters wont work - you will need to recreate those.

It will be a lot more work though.