[borag]

I'm tired of the overcalls over 1N and also tried a few systems with weak or strong notrump.
My favorite is Nigthmare (modified).

But what about this one, too crazy ?
Simply 2N = 15-17 bal no 5M ?

1♣ = 10-21 unbal 5+c, 4414, strong (41)44
1♦ = 10-21 unbal 5+d, 4441, weak (41)44
1♥ = 10-21 unbal 5+h, 15-19 if balanced
1♠ = 10-21 unbal 5+s, 15-19 if balanced
1N = 11-14 bal 5M ok
2♣ = 20+ bal or 22+ any
2♦ = 0-6 unbal 5+M, 18-19 bal no 5M
2♥ = 7-10 unbal 5+h (good suit)
2♠ = 7-10 unbal 5+s (good suit)
2N = 15-17 bal no 5M

[BunnyGo]

I'm not sure I like the 2NT bid, you may frequently find yourself too high. Recall all the hands when you open 1NT 15-17, partner passes and you make on the nose. At matchpoints this is a push across the field, except you get a zero now. Worse, how can partner ever invite you with the safety of stopping in 2NT?

Why not modify the system where 2NT = 20-21? You can open 1m with 15-17 NT and rebidding 1NT.

[borag]

That's because it's hard to show a 15-17 bal hand after overcalls and support.
This is what I played in the past

1♣ = 10-21 unb 4+c or 15-17 bal but created problems

After switching to Nightmare

1♣ = 15-17 bal, 15-21 unb 4+c or 22+ any

You are not well positioned with 4414, 4405, (43)15
What we tried was

1♣ = 15-17 bal, 15-21 unb 4+c or 22+ any
1♦ = might have 10-14 unb (41)35
2♣ = 10-14 unb 6+c
2♦ = 10-14 unb 4414, 4405, (43)15

But too many variants

[Flameous]

All I can say is that Zia played 12-14 2NT opening. (Only NV I think)

For each his own...

[RunemPard]

15-16 HCP instead? Just add 17 HCP to 2D (17-19?)