We open ALL hands between 7 and 13 hcp. We pass ALL hands 0-6 or 14+ (1st and 2nd seat).
When we open, we usually show the exact number of cards in a major (or both). Usually we deny length in the other major. Exception: the 1c (in 1st and 2nd) and 1h (3rd, 4th) openings can contain also 4 spades (if 11-13 hcp). When we open a minor, we deny lenght in both majors (0-3 hearts, 0-3 spades). With a 4 card major and a longer minor, we always open with the major.
use 2s as an escape sequence when we get doubled in 2h and partner has something like 2-1 majors
pass - 1c
The following bids are simmetric and apply both after (pass - 1c - ?) and after (pass - 1c - 1d - ?)
Assume x is the 2-under opening
Exception: after 3s
After 3nt opening