Beans and Rice = Complete Protein?

I've heard from several different sources that beans with rice = complete protein.  How does this work, and is it sufficient to just eat beans by themself?

I'm not sure, but it's something to do with the amino acids that beans and rice each have. They compliment each other to boost the protein above what you might get if you ate them on their own. Beans and dairy complement too, so beans and cheese...

I'm happy with my protein intake and I eat beans by themselves. Whether it's "sufficient" or not is beyond my nutritional knowledge.

Protein is made up of amino acids and when all 12 amino acids are present, it is considered complete protein.  It is ideal to get all the amino acids hence the reason to pursue complete protein.

Many foods (meat, eggs, chicken, etc) provide complete protein but others like beans do not have all the amino acids.  One source of the missing acids is carbs like beans and rice.

This site has a more detailed explanation: LINK 

Actually they have proved that you don't need to 'combine' in order to achieve the amino acids.  That original thought was a theory by a woman who now admits that she may have made too big a deal out of it.

I beleive it is a complete protein, but one thing is for certain, it is completely delicious!