Your friend has it right in this case. There are three types of normal save - an amour save, a cover save and an invulnerable save. You can only take one save, no matter how many types of save you have. Check out P24 of the rule book - "Models with more than one save".I'm still a bit confused on how Invulnerable saves work, in the book it states that they can be taken if a model takes a normal wound. I'm saying that I can use it whenever a model fails an armor save, however my friends say you use it for AP weapons, instant death, etc (anything that removes a normal save). Can someone clear this up please?
Thanks in advance.
There are some special rules that allow another roll to ignore the wound, but these aren't generally referred to as saves. Things like Feel No Pain, or the necrons We'll Be Back rules fit in to this category.
Hope that helps
[Edit: Ninja'd by Necrosis ]