Clearly...

Playing my first game of Stratego with one of the boys...

Me:  How does the game end?
Him:  What?
Me:  How can you tell when someone has won?
Him:  (cheerful assurance)  They say, "Look, I won!"

And another obvious answer...

Brother 1 to Brother 2:  (Dressed in a clone trooper mask, Power Ranger gloves, elbow pads, knee pads, laser tag vest on chest, plastic shield strapped to back, bungee cord around waist to hold small weapons, bathrobe sash tied across chest to hold larger weapons)  (with confidence) I look cool, right? 

Brother 2:  (emphatically) Yeah!