We have a strong hand, and are about to open with 1 or 1, when leftie rudely sticks in one of a suit. What now?

The solution is the use of the strong double – a double of one of a suit showing 16+ points and any shape.

WestNorthEastSouth
1pass1
dbl
16+ points, whatever their bids meant.

Opposite this, all responses retain their structural significance, but because of the wide range of the double, the response ranges have to be stretched. Everything is fine opposite partner's double of 1, because 1 can be used as the negative. And if they bid over the double, all weak hands can pass.

But opposite a strong double of 1, 1 or 1, we have to compromise with the one-level responses. A one of a major response shows at least four cards and is forcing, but does not guarantee any points. A 1NT response is anything without a major up to six points.

After a one-level response, doubler should not break the 1NT barrier without the equivalent of a 1 opening. Two-level responses can be kept up to strength: at least seven points.

WestNorthEastSouth
1dblpass
1pass1NTpass
2
1 showed at least four spades, no heart suit, unlimited and forcing, but not promising any points. 1NT limited East to a hand that would have opened 1 i.e. 16-20 points. And now 2 breaks the 1NT barrier and shows 7+ points and exactly three hearts. We are back on terra firma neutralis.
WestNorthEastSouth
1dblpass
2
At least seven points with diamonds the only suit, unlimited and therefore forcing, whatever 1 meant.

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