So, in the game that I'm developing the over all economy can really be hurt if an exploiter was to hack other's leaderstats or even their own. I know of several ways to keep leaderstats safe but I'm hoping some of you guys will leave some ideas/suggestions. It would be greatly appreciated.
If your game isn't FE the simplest way is to not trust the client. (Which is what FE is based off of already so :shrug:)
Anyways: Some of the best ways to do this is for all, should-be, constant values, is to connect a .Changed event to a value which makes sure that the value doesn't change. For values that sometimes or often change, it gets a bit harder. At this point you most likely want to provide "reasons" for why they're changing. You could do this by string values, or, more likely, remote/bindable events/functions. If I'm not mistaken you can still use them even when the game isn't FE.
Personally, I highly recommend you start FE scripting as not only does it give the server more advantages but it also requires you to think outside the box. When FE is disabled, you'll have to focus on much tinier but more frequent exploits. I encourage you to think how the exploiter thinks and counter it. Best of luck to you and if you require more information feel free to ask!