The hand is a review of the "Take Out Double"

After the "Double" by West, North will pass.  His partner didn't bid.  East is now forced to bid.  Bid 1 Heart.  West will pass.  If East had a big hand  9+ he would jump a level.

North opens 1D.  With 3-3 open the higher suit.

Ease bids 2 Clubs.  Great suit.

South "doubles".  Called a "Negative Double" tell both the unbid suits and at least 10 points.

North bids 2 Spades.  

South is minimum so Passes.

South makes  "Negative double" tell his partner he has at least 4-4 in the unbid suits and 10 points.

North Bids 3NT.  Partner has at least 4 Hearts and between them at least 8 Diamonds.

North Opens 1 Diamond

East bids a Spade

South Doubles showing both unbid suits.

North can't take either suit so rebids his Diamonds.

South passes.  He does not have enough points for game in a minor, so stop.

North opens 1 NT

East bids 2 Clubs.

South would like to use Staymen, but East too his bid.  Double saying "Stole my Bid". 

North knows it is not a "Negative Double" since there are not two unbid suits. North answers "Staymen" 2 Diamonds. 

South bids 3NT with 11 points.

North opens 1 Diamond

East Doubles.

South Passes

West bids 2 Spades.  10 Points.

North may rebid the Diamonds.  Because of the double by East he is denying Diamonds so South may have some.  Plus North has a good hand.

East with a suit agreement - Spades- East adds 3 points to his hand and bids 4 Spades.