[Box nearby, Trunks starts setting up the planks in arrangement, building the tower. When it's finished it's a little taller than Goten, given they're using bigger blocks of wood than normal.]

It isn't at first. The point of this game though, is to take planks from the bottom, and move 'em to the top of the tower. But without topping the whole thing over.

[Studying it for a moment, Trunks then selects one of the pieces on the outside of a row, and moves it to the top.]

Like that. We take turns. At first it's not so difficult, but it'll get harder the more we build. That's how it's a test of balance.