Mini NT is opened in 1st or 2nd seat NV only. For obvious reasons it’s not safe to open a mini NT vul, However; it’s also not safe to open in 3rd or 4th seat as your partner is likely to have less than 10 pts., possibly a lot less in my version of Precision. Our goal is to provide a relatively simple system that can be used over a mini NT and does not involve transfers. This has to be simple as we already have to remember a system over a medium NT that is also partially used over 1N rebids.
Pass: 0-12 HCP some hands are better than other, therefore would not pass all 12 HCP hands
2♣: non-forcing Stayman. Garbage Stayman is not used so opener may cooperate in penalizing interference over 2♣.
2¨: forcing Stayman
2©/2♠: weak sign-off
2N: Invitational 13-14 pts
3♣/3¨: Preemptive 6+ card minor
3©/3♠: Preemptive 6+ card major
3N: sign-off to play
4¨: asks for exact pt. count, 4©=10, 4♠=11, 4N=12
4©/4♠: sign-off to play
Bidding after 2♣ non-forcing Stayman
2¨: denies a 4 card major
2©: 4 hearts may have 4 spades