This "quick tutorial" introduces the general idea of a call and explains the most common cases. It does not explain or illustrate all cases. For additional details and/or examples, refer to the links in the "MORE INFO" box.
The beginning of Turn and Deal is very similar to the beginning of 1/2 Tag. For both calls, the dancers begin by turning toward the center of the line and walking in that direction. The difference is that in a Turn and Deal each dancer turns 1/2 (180 degrees) to face the opposite wall, while in a 1/2 Tag they only turn 1/4 (90 degrees).
If the dancers in each half of the line start as a couple, they will be turning together in the same direction (either both left or both right), and they will end as a couple. The dancers in each couple will be facing the opposite wall from when they started.
In a Turn and Deal from a one-faced line, since there are two couples facing the same wall they will both be facing the same wall -- the opposite wall -- when they are done. So the result will be one couple in front of the other.
Note that this result is very similar to a Wheel and Deal from a one-faced line, for the same reason. Everybody is turning around halfway, and the dancers from one couple end up in front because they were "passing right shoulders" with the dancers from the other half of the line. The difference between these two calls in this case is that in a Turn and Deal, because the dancers are turning individually, they switch their positions within the couple -- the beau becomes the belle and vice versa.
If the dancers start in a mini-wave, as they turn toward the center of their line one of them will be turning left and one will be turning right. They must each continue turning, individually, in that same direction until they are done. You may find this confusing at first -- just concentrate on turning in your own direction and don't worry about what the other person is doing.
In this case, because the dancers are turning individually, the dancers will end up together again in a mini-wave but holding the opposite hand. If they started in a right-handed wave they will end in a left-handed box. If they started in a left-handed wave they will end in a right-handed box.