Ekren 2D (Two Diamonds)

Ekren is a preemptive 2 opening bid, showing at least 4-4 in the majors and 3-10 HCP. It has become a popular convention in Scandinavia, and has appeared on the convention card of Norwegian expert Geir Helgemo, among others.

Response	Meaning
2	Signoff.
2	Signoff.
2NT	Strong, artificial inquiry of opener's distribution (see below).
3	Natural, 6+ clubs, non-forcing.
3	Invites game, 3-3 in and .
3	Weak, preemptive.
3	Weak, preemptive.
3NT	To play.
4	To play.
4	To play.

Opener's weak bid is 3. Any other rebid is game-forcing.

Opener's Rebid	Meaning
3	Showing a minimum. Responder can bid 3 as a second relay, in which case opener's rebids are: 3 to show 5-4 in and . 3 to show 4-5 in and . 3NT to show 4-4 in and .
3	5-5 in the majors. A 3/ rebid by responder is slam-invitational and forcing.
3	Maximum, 5-4 in and .
3	Maximum, 4-5 in and .
3NT	Maximum, 4-4 in and .

Ekren is not a Brown Sticker Convention under WBF rules. However, it is disallowed in ACBL events. The ACBL's General Convention Chart requires two-suiters at the two level to show at least 5-4 with 10 points. The closest playable variation would be an ACBL Midchart convention: a 2 opener that shows at least 5-4 in the majors. Per the ACBL's Midchart rules, players using this convention would be required to provide the opponents a written defense.

Ekrens was created in the 1990s and is named for its inventor, Bjorn Olav Ekren of Norway.