I’m pretty new with multiplayer, so I want to give each players in my game stats (health, power, etc) and I wanted to know if I should save this kind of data into a server in order to secure them, or can I only make a local save ?
Local save can be edited, so if your game is not competitive and cheating players ruing game only for themselves i think it is fine. However if you plan microtransactions or anything PVP you must have backend.