@chai2,
Only if they repeat such as madam...if your word uses an a, or a m...there repeating, but your only using the same letters so it counts as three...If you use an a, m, and d in your next word...
It doesn't really matter much, I actually like the thinking to use as many as you can and still make it 6 letter words...But yes, when I made it, I intended for 6 letter words, reuse 3 letters...but no you don't have to be limited...if you don't want too..
