In reply to Rob Naylor:
Thumb war. Hook the fingers of your right hand round the fingers of your opponent's right hand. First one to trap the other person's thumb wins.
Leg wrestling. Like arm wrestling, but you lie on your backs, buttock to buttock, and you cross right legs. you try to bring your opponent's right leg over to your left.
Spelling game. First person says a letter. Second person says another letter. Each subsequent player adds another letter. You are out if your contribution makes a word (hint: its a bad idea to start with "a").
You are also out if you are challenged and the letter you added cannot be used with the words before to make a word. (hing: if the first person says "q" and you are second, don't say "x").
But if you challenge someone and they can make a word, you are out (hint: don't challenge the second person if they say "u" and the first person said "q").
Once a word is completed, start another word. Lots of tactics here.