When your partner makes a takeout double, your "response" shows two things:

1) Your best suit (or notrump)

and

2) Your strength

It continually amazes me how many intermediate-level students get part 2 wrong. They respond to a takeout double as if they are responding to partner's opening bid. Contrast the following two situations:

West	North	East	South
	1	Pass	??

versus

West	North	East	South
1	Double	Pass	??

In each case, suppose South holds:

 65  
 KQ87  
 A32  
 J765
 

In the first auction, he responds 1 and the opener must bid again (1 is forcing one round--it shows 6+ points).

The second auction is very different! South must not bid 1. It does not show 6+. It shows 0-8. His partner doesn't have to bid again. When responding to a takeout double, a non-jump (such as 1) could be a very bad hand. What is South to do with, say,

 432  
 5432  
 432  
 432?

He can't pass and defend against 1 doubled. He must take out to 1 (0-8). If he had the same hand when his partner opened 1, he could just pass and let partner play in 1.

Once you understand and remember the difference, the schedule of responses (listed below) to partner's takeout double is logical. In the chart, notrump bids are also shown. Those are treated a little bit differently than taking out to a suit (with the explanation being shown in the chart).

After partner's low-level takeout double (responding to high-level takeout doubles will be covered in the next article/quiz), bid as follows:

Non-jump suit bid=0-8 HCP and at least a 4-card suit (occasionally it will be a 3-card suit as you will see in one of the quiz answers).  Example: 

West	North	East	South
1	Double	Pass	2

 A4  
 652  
 J6532  
 762
 

Single Jump in a suit=9-11 HCP and at least a 4-card suit (INVITATIONAL--the doubler can pass).

Example: 

West	North	East	South
1	Double	Pass	2

 A3  
 AJ762  
 5432  
 54
 

1NT = 6-10 balanced and the opponent's suit stopped.
2NT = 11-12 balanced and the opponent's suit stopped [INVITATIONAL].
3NT = 13-15 balanced and the opponent's suit stopped.

Those are the basic ways to take out partner's takeout doubles. Here are a few other possible ways to take out the double:

Double jump = 6-card suit, semi-preemptive (this is my modern-day recommendation--in some books, this is defined differently)

Example: 

West	North	East	South
1	Double	Pass	3

 5  
 KJ8765  
 54  
 J765
 

Jump to game = Usually a 5+ card suit and enough for game (good hand). Example:

West	North	East	South
1	Double	Pass	4

 654  
 AKJ65  
 3  
 KJ52
 

Cuebid = Game forcing (opening bid strength) -- not sure where you are headed. Example:

West	North	East	South
1	Double	Pass	2

 AQ76  
 KJ65  
 32  
 A106

If the takeout double is after a preempt, the same basic principles apply (there will be an example in the quiz).

You might also consider getting Larry's book on Doubles and Redoubles HERE or try Michael's Doubles Webinar which you can find HERE.