Mula, im guessing that this is mule/donkey and therefore a usage specific to dominoes ie one cant say una cama mula  for double bed or "que sea mula"  for make it a double.

Would you please provide a few sentences using "mula"?  It is new to me as well and I am not sure if I know how to use it correctly. 

Thanks.

No se como jugar dominoes. But I found this link to a simple instructional video. Can anyone tell me how you get the film itself to transfer here to the SpanishPod discussion section? Gracias Abuelo Jack

 http://www.videojug.com/film/how-to-play-dominoes

paste the same link into the first field of the dialogue that opens when you click on the filmstrip icon in the editor toolbar.

change the second field to "open in new window"

whatever you put in the third field will appear in the tooltip when you mouse over the link.

enjoy

Me gusto mucho jugar dominoes y a mi trabajo la gente jugan por dinero. Pues no entiendo porque JP usa son y no "hay".  Cuando usas "hay"?  Ayudame, por favor.

Gracias, Bob 

My own personal rule (not sure if the grammar bosses agree) is that when you're talking about the existence of objects, you use "hay."  E.g., "Hay fichas en la mesa." There are some dominoes on the table. There could be three, there could be a set, there could be two sets.  You could even specify a number, but as long as you're not referring to a complete set, you use "hay."

However, when you're referring to a complete set, then you'd use "ser."  Las fichas son 28 en total.  There are 28 total tiles (in a set). 

You'll also use "ser" when talking about the Three Wise Men because they are set.  Los Reyes Magos son tres.  There are three wise men.

And you'll use "ser" when the host greets you at the restaurant "Buenas noches, ¿cuántos son? Somos cuatro."  Good evening, how many?  There are four of us.  If your reply is "hay cuatro personas," you may be implying you're not part of a complete set.  Maybe there are four people in the lobby, so what, how are they related? 

Hope that helps!