Source: Ruff and Sluff is considered the cardinal sin in Bridge. Many Bridge players think like this: If I ever give a ruff and a sluff, I will be the talk of the town. Next time I am in a Bridge tournament, I can see them pointing at me; I can hear them whispering: Amit is such a weak player — you know what he did in the last tournament? In this column I will give you examples when Ruff and Sluff (R&S) is the correct defense. There are two types of situations when R&S is the right thing to do: 1) Giving declarer a useless R&S rather than a finesse that he cannot take otherwise and 2) setting up a trump trick by doing so. I. R&S Type 1 — giving declarer a useless R&S
Dummy 10 7 5 3 A Q 10 3 2 Q 5 3 2
You J 9 6 2 8 7 6 2 10 8 7 6 3
The contract is 5. Trick 1. Partner leads the 5 and you win the Q Trick 2. You play the A which declarer ruffs. Declarer started with 1 spade. Trick 3. Declarer cashes A Trick 4 Declarer cashes the K. Partner shows out. Declarer started with 5 diamonds. Trick 5-7 Declarer plays A, K, Q. Partner follows all three times. Declarer started with 3 hearts. Hence he started with 4 clubs. Trick 8 Declarer plays a to your Q. What do you return? Returning a might give him the contract. For example the suit might look like:
A 8 7 2
Q 3  J 9 5
 K 10 6 4
But playing another heart although gives a ruff and a sluff cannot allow the contract to make as declarer started with 4 clubs. II. R&S Type II— Creating a trump trick for Defense
Dummy A K Q 5 A K 8 7 J 4 9 4 3
You 4 3 2 10 9 K Q 9 7 3 2 A 10
Auction goes:
West North East South
2 Dbl 3 Pass
Pass Dbl Pass 4
Pass Pass Pass
Amit’s rule: If the opponents want to play in Gerber (4) or Derber (4; this word is my invention), let them. Trick 1. You lead the K of D which holds. Partner plays the T (attitude for A). Trick 2. You continue with the Q of D which holds. It is clear that partner has the A of D and declarer is out of Ds. How do you continue? Trick 3. Two things should catch your attention. The T of trumps that you have and the major suit strength in dummy. So continue with D and give a ruff and a sluff. R&S type2. When declarer next plays trump, win declarer’s K with the Ace and play a 4th D. Partner ruffs with the J and your T becomes the setting trick. References: Example 1 is from Official Encyclopedia of Bridge published by ACBL. Example 2 is taken from “The Deadly Defence Quiz Book” by W. Izdebski, R. Krzemien, and Ron Klinger