The complexity is exponential.
The base case aside (when n is < 2), each call to the method will call itself two times. You can draw a binary tree representing the call. For example if you call magic with 5 as a parameter:
The tree is not perfectly balanced but it doesn't change the big O notation, which is O(2^n).
Your algorithm is a fibonnaci sequence algorithm, so you can read plenty about it on the internet, including how to change its complexity to polynomial time.