CRASH

CRASH (aka "CRO") is an overcall structure against an artificial 1 opening. The acronym stands for "Color, Rank and Shape", in reference to the types of two-suiters shown.

Multiple variations of CRASH exist. After an enemy 1 opening bid:

Variation #1

This is the original convention as created by American experts Kit Woolsey and Steve Robinson.

Overcall	Meaning
Double	Strength-showing
1	Two suits of the same Color, i.e. + or +
1	Two suits of the same Rank, i.e. + (the minors) or + (the majors)
1	Natural, may be light
1NT	Two suits of the same Shape, i.e. + (the rounded suits) or + (the pointed suits)

Variation #2

Overcall	Meaning
Double	Two suits of the same Color
1	Two suits of the same Rank
1	Natural, may be light
1	Natural, may be light
1NT	Two suits of the same Shape

Variation #3

Overcall	Meaning
Double	Showing hearts
1	Natural, may be light
1	Two suits of the same Color
1	Two suits of the same Rank
1NT	Two suits of the same Shape

Variation #4

Overcall	Meaning
Double	Showing hearts
1	Showing spades
1	Two suits of the same Color
1	Two suits of the same Rank
1NT	Two suits of the same Shape

CRASH can also be used over a 1NT opening bid:

Overcall	Meaning
Double	For penalty by an unpassed hand. By a passed hand, shows two suits of the same Shape
2	Two suits of the same Color
2	Two suits of the same Rank
2	Natural
2	Natural
2NT	By an unpassed hand, shows two suits of the same Shape

CRASH vs. 1 is permitted by the ACBL General Convention Chart (GCC), but not allowed against 1NT.