"Why, you don't know the rules; you'll be a month learning them.

And then it's no joke playing-up in a match, I can tell you--quite another thing from your private school games.

Why, there's been two collar-bones broken this half, and a dozen fellows lamed.

And last year a fellow had his leg broken." Tom listened with the profoundest respect to this chapter of accidents, and followed East across the level ground till they came to a sort of gigantic gallows of two poles, eighteen feet high, fixed upright in the ground some fourteen feet apart, with a cross-bar running from one to the other at the height of ten feet or thereabouts.
"This is one of the goals," said East, "and you see the other, across there, right opposite, under the Doctor's wall.

Well, the match is for the best of three goals; whichever side kicks two goals wins: and it won't do, you see, just to kick the ball through these posts--it must go over the cross-bar; any height'll do, so long as it's between the posts.
You'll have to stay in goal to touch the ball when it rolls behind the posts, because if the other side touch it they have a try at goal.