independent skills: fishing and cooking regardless of what you fish, you can sell those fish and buy other fish to cook. they are independent because you cannot train them both at the same time without linearly giving up xp in the other one. the most efficient fish to cook has no dependence on what the most efficient fish to fish is. dependent skills: mining and smithing because you can smith gold while mining it WITHOUT giving up any mining xp, it is better to smith the gold while you mine it rather than mine gold, sell it, and buy addy bars to make platebodies with. the most efficient ore/bar to smith has dependence on what the most efficient ore to mine is.