One Click is Detected as Multiple Clicks TLDR: 
I don't know how to fix it so that 1 click = 1 click. 

Brief background: 
I'm making a "lock-picking game" with six pins (objects A-F) that must line up to "unlock". They start at different positions and some control other pins. 

THE PROBLEM: 
When I'm running my game in BGE and click once on an object, the game detects multiple clicks and therefore performs the resulting action (moving forward one unit and adding 1 to their counter) multiple times. Since it adds however many clicks it detects to the "counter" integer property attached to it, I can see that the number of clicks it detects each time is random.
***I don't know how to fix it so that 1 click = 1 click. Please help.

I feel like there should be an easy solution but I'm having trouble finding it. I don't see anything in user preferences or the System Preferences app (I have a MacBook Air). I know that it's probably registering a number of clicks depending on how long I hold the button down in a click for, but I don't want that.

Also, I'd rather use logic blocks because I'm not too familiar with Python, but if that's what it takes and you have clear instructions and copyable code, I'll take it. 

Thank you so much, I appreciate any help I can get!
Make sure that your sensor (whoever clicks)is set to tap mode