Well from my experience Manuals always give basic crap info a hardcore gamer like me already knows. like what HUD is , what minimap does , where your ammo count is and all
And if you come across a complex game? You will eventually have to check.
The point I made is this... Why waste a few mins going online to a forum to ask a basic question that can be quickly looked up on and that can be explained clearer than someone else posting, and from there actually read more and understand more.
Some games have unique systems in perhaps making of items etc, Sacred 2 had an annoying system of stuff, great game but if you didn't read the manual you would get a bit lost in how to craft things.