I'll try to remember a game I played as best as possible without making it sound weird haha.
What we did (I was in 4-H for this) was place lead ropes around certain supports in the arena. We had to get a certain about before the other rider and practice tying safety knots and when we got them all right (and when I say all, I mean we each got like 2 or 3), we had to trot back to the center of the ring before the other person. But if you kind of forgot how to do a knot you had people on the ground that were there to kind of guide you so you could get it. But they didn't tell you how to do it, they gave like, hints that helped! Hope I didn't make that sound too confusing!
So it's not the greatest or most fun game, but it tested our knowledge in a way about safety knots in case you have to tie your horse somewhere so you know how to do it in case something were to happen that the horse could undo the knot. We also just put it into like a racing type of game where like I said, you had to get to the middle of the ring before the other person did.