The King of OX is an easy and fun game of selecting "O" or "X" as fast as you can. As a teacher, you have to grade student's math test. It's incredibly simple but insanely addictive. SIMPLE and ADDICTIVE game play! Rule is so simple. Just select "O" or "X". If the answer of test is right, touch "O" or "X". Once you start, you can't hardly put it down. GREAT SOCIAL gameplay!