How The Dealer Plays Their Hand
The dealer must play his black jack hand in a specific way, with no choices allowed. The Black Jack table should be clearly marked whether the "Dealer Stands on all 17's" or "Dealer hits on soft 17's." 

Dealer Stands on all 17's
This is the most common rule. The dealer must continue to take cards until their total equals 17 or higher. 

Dealer Hits on soft 17's
The difference here is that when the dealer has a soft total of 17.  Hands such as (Ace,6),  (Ace,5,Ace), and (Ace, 2, 4) are all examples of soft 17.  The dealer hits these hands, and stands on soft 18 or higher, or hard 17 or higher.  This method reduces your odds of winning.

 

6 Decks - Playing with a Hard 17
HARD TOTALS	Dealer's Upcard
Your Cards	2	3	4	5	6	7	8	9	T	A
17	S	S	S	S	S	S	S	S	S	S
16	S	S	S	S	S	H	H	SH	SH	SH
15	S	S	S	S	S	H	H	H	SH	H
14	S	S	S	S	S	H	H	H	H	H
13	S	S	S	S	S	H	H	H	H	H
12	H	H	S	S	S	H	H	H	H	H
11	D	D	D	D	D	D	D	D	D	D
10	D	D	D	D	D	D	D	D	H	H
9	D	D	D	D	D	H	H	H	H	H
8	H	H	H	D	D	H	H	H	H	H
Key:	H	Hit
	S	Stand
	D	Double if allowed; If not, hit.
	SH	Surrender if possible otherwise hit

What is Surrender?
Surrender

The decision to surrender must be made before any other choice about playing your hand. Surrender may not be an option, but if it is you need to know what it is.