Source: 

Drury is a conventional 2club suit response by a passed hand after partner opens 1Heart Suit or 1Spade Suit in third or fourth seat. The 2club suit bid is artificial, showing a limit raise with 10-12 support points and 3+ card support.

Playing Drury, responder can keep the bidding low at the 2-level instead of making a jump raise. Since many partnerships open light in third or fourth seat, responder wants to bid conservatively opposite a weak hand.

Opener’s Rebids

After opening 1Heart Suit and hearing a 2club suit response, opener’s rebids are:

Opener’s Rebid Meaning
2Diamond Suit A sub-minimum hand (10-12 points)
2Heart Suit A normal opening bid (12+ points)
All other bids Natural, with normal opening values (12+ points)

After opening 1Spade Suit and hearing 2club suit:

Opener’s Rebid Meaning
2Diamond Suit A sub-minimum hand
2Heart Suit Natural, 4+ hearts, but does not guarantee a full opening bid
2Spade Suit A normal opening bid
All other bids Natural, with at least normal opening values

Examples

North South
Spade Suit864 Spade SuitAJ92
Heart SuitAKT Heart SuitQJ987
Diamond SuitK752 Diamond Suit6
club suitT83 club suitQJ2
West
Pass
Pass
Pass
North
Pass
2club suit (1)
2Heart Suit (3)
East
Pass
Pass
All Pass
South
1Heart Suit
2Diamond Suit (2)
  1. Drury, showing 3+ hearts and 10-12 points.
  2. Showing minimum strength.
  3. Signing off.