The origin of these conventional preemptive bids is unknown. The basic guidelines for such an opening on the two level, except an opening of the strong, artificial 2 Clubs opening, are shown below. All openings on the two level are weak without exception. All overcalls on the two level, which fall within these parameters without ambiguity, also fall under the definition of concept preempts and are treated in the same manner.

Note: there are only six such possible overcalls on the two level, which qualify.

The range of the weakness in values is determined by partnership agreement. The partnership can also base the Concept Preempt bids on the Losing Trick Count method in relation to the state of vulnerability. The responses are per partnership agreement and may be varied and/or modified to meet the needs of the partnership.

The main concept is deemed obstructive for the opponents.

2 :	Promises either a 6-card (plus) Diamond suit, or a 5-card (plus) Heart suit.
2 :	Promises either a 6-card (plus) Heart suit, or a 5-card (plus) Spade suit.
2 :	Promises either a 6-card (plus) Spade suit, or both Minor suits of at least 5-5 distribution. (Optional)

Example 1

South KQ8643 87 QJ6 54		North A975 AK10 A983 KQ
2				A two-bid in Spades shows either a 6-card plus Spade suit, weak values, or both Minor suit with a distribution of 5-5.
		2 NT		With possible game values the responder will relay with the next higher-ranking bid, (not suit), in order that the opener may clarify the holding.
3				The opener communicates that the opening bid is a 6-card plus Spade suit.
		4		The responder holding game values bids the game contract.

Example 2

South 3 87 QJ986 KQ864		North AJ5 AK10 A983 A109
2				A two-bid in Spades shows either a 6-card plus Spade suit, weak values, or both Minor suit with a distribution of 5-5.
		2 NT		With possible game values the responder will relay with the next higher-ranking bid, (not suit), in order that the opener may clarify the holding. The responder must relay first in order to discover which holding and then continue, if the contract can be improved.
3				The opener communicates that the distribution of the holding is 5-5 in both Minor suits.
		3 NT		The responder holding game values bids the game contract in No Trump.

Note: This conventional method is categorized as a Brown Sticker, meaning that the bid is lacking an anchor suit or at least one specified and known suit. Such opening bids are legal only in special events and World Bridge Federation final rounds at sponsored and designated bridge events.

If you wish to include this feature, or any other feature, of the game of bridge in your partnership agreement, then please make certain that the concept is understood by both partners. Be aware whether or not the feature is alertable or not and whether an announcement should or must be made. Check with the governing body and/or the bridge district and/or the bridge unit prior to the game to establish the guidelines applied. Please include the particular feature on your convention card in order that your opponents are also aware of this feature during the bidding process, since this information must be made known to them according to the Laws of Duplicate Contract Bridge. We do not always include the procedure regarding Alerts and/or Announcements, since these regulations are changed and revised during time by the governing body. It is our intention only to present the information as concisely and as accurately as possible.