What do you mean Rugby?

I was tending to Brayden upstairs.  Carter and Luke playing in the basement.  I hear Luke cry (I do not do anything else someone comes to get me...part of having boys).  Then I hear Carter comforting him in the kitchen.

I made my way to the kitchen found Luke had an ice pack on his foot.  I asked what happened.  Here is explanation.

Luke, "Carter told me that we were going to play rugby."
Carter, "That's right.  I set up the goals and everything."
Luke (half crying), "Then Carter said go, I had the ball and he tackled me hard.  I thought we were going to play rugby and roll around on a rug."
Carter, "I guess Luke didn't know what rugby was."