SCUM

SCUM is defensive convention against a 12+ HCP 1NT openning. It is an acronym for "Shape, Color and Majors", which refer to the conventional calls of Double, 2 and 2, respectively. Each of these calls represents a particular two-suited hand with at least 4-4 length.

Double 2 suits of the same Shape, i.e. / (the rounded suits) or / (the pointed suits). Advancer is expected to bid 2 with club tolerance, or else 2.

2 2 suits of the same color, i.e. / or /. Advancer should pass or correct.

2 The majors.

2 Natural.

2 Natural.

2NT The minor suits.

Origins

SCUM was invented by American expert Bart Bramley. A full writeup is available in the 3/12/07 ACBL Daily Bulletin. According to Bramley, "The ambiguities of the system (double and 2) are coupled. Once you know one suit, you know the other. Other systems don't have this. For example, in DONT 2 is clubs and a higher suit, or in Cappelletti, 2 is hearts and a minor. There's no connection between the lower-ranking suit and the higher one in those systems."

Double	2 suits of the same Shape, i.e. / (the rounded suits) or / (the pointed suits). Advancer is expected to bid 2 with club tolerance, or else 2.
2	2 suits of the same color, i.e. / or /. Advancer should pass or correct.
2	The majors.
2	Natural.
2	Natural.
2NT	The minor suits.