I've always been curious about this. My friends and I used to play Risk for hours but we created our own version called "capitals". Essentially, you got dealt 3 cards at the beginning and you picked one to be your "Capital" and placed it in the middle face down. When someone took over your capital, you lost and the person who conquered it took all your cards and your pieces. Made it a little more interesting and the regular brute, load up on bonus pieces method.