Strong opening bids 2♦ - game force:

• 24+ HCP, balanced distribution;

• 23+ HCP, unbalanced distribution.

Responses:

• 2♥ - 0-7 HCP, no aces;

• 2♠ - 1 ace in a major;

• 2NT - 8+HCP or 2 kings, no aces;

• 3♣ - A♣;

• 3♦ - A♦;

• 3♥ - 5+♥, no aces;

• 3♠ - 5+♠, no aces;

• 3N - 2 aces.

If you use 2♦ opening 2♣ does not force a game.