These lectures give an elementary introduction to the concept of effective field theory (EFT) and its applications in strong interaction physics. The emphasis of the lectures is set more on the foundations rather than specific calculations. The plan of the lectures is:

Lecture 1 The basic ingredients underlying EFT are explained. A cornucopia of examples is given to show the universal applicability of EFT. The paradigm shift in quantum field theory and the general structure of EFTs are also discussed.

Lecture 2 A simple model consisting of a light and a heavy scalar field is discussed to learn about many features of EFTs. This includes the concept of matching, renormalization group flow, decoupling and triviality.

Lecture 3 This lecture gives a simple introduction to the chiral dynamics of QCD, including the Goldstone theorem and its consequences, a derivation of the power counting, quark mass ratios, the inclusion of matter fields (baryons) and bound state EFTs.

Lecture 4 In this lecture, a systematic discussion of hadron-hadron scattering is given. Such reactions serve as tests of various QCD symmetries. This includes pion-pion, pion-kaon, pionnucleon, kaon-nucleon and Goldstone boson scattering off D-mesons.