Any magic system needs limits. This I've learned as I have done research. In fact, I subconsciously made a limit to my own magic that I only noticed as I prepared Chapter One of my book to send off to my new test reader. My magic is powered by two things, one the power source is from the planet itself, two the wizard's energy level. This means that if the wizard is tired they cannot cast much magic. I take this one step further by also having it where if the wizard casts magic while hungry they have a ravenous appetite that forces them to consume a lot of food. A wizard can waste away if they don't eat after a few minutes. Of course, eating a bunch of food quickly has a rather embarrasing side effect that the Italian views as a huge complement but that's just my silly side surfacing. Anyhow, what do you think of my limit? Do you guys have an interesting limit to your magic system? If so let me know so I can compare notes.