Read the following dialogue and answer the question.

Mother: Hi, sweetheart. How is school?

Luke: It's great. We're preparing for sports competitions next month. All schools in our regency are joining. 

Mother: I have heard about it from your teacher. Are you joining one type of competition only?

Luke: I am joining three competitions, Mom.

Mother: Wow, cool. What are they?

Luke: Swimming, badminton, and chess. But I am not sure about chess. Many students in my school are good at playing chess.

Mother: Don't worry. I think they're going to choose you. Just do your best. Go get change and prepare for dinner.

What is Luke and his school preparing?