[Free]

Does anyone have a good defense against Raptor 1NT overcalls?

[FrancesHinden]

I think it's a good idea to keep the same principles as after other overcalls e.g. if you usually play a lot of transfers after intervention, you might play transfers here. We ended up agreeing something fairly simple:

1S - (1NT) -
dbl = random values, usually balanced, forcing pass at the 2-level
2C/2D = natural, F1
2H = good(+) 3-card raise
2NT = good 4-card raise
3m = fit

a hand with long hearts doubles then bids hearts

1H - (1NT) similarly, although obviously 2S is a 3-card raise to the 3-level

After 1C - (1NT) you either do the same, or you treat their 1NT call as (effectively) an overcall of 2 of their minor. 1C - (1NT) - is the same as 1C - (2d) - except that you have a 2C bid available. So you can play transfers here, if you play transfers after an overcall (e.g. 1C - (1NT) - dbl = hearts, 2C= spades, 2D = good raise etc)

But if you don't usually play transfers, don't play them here...

[dake50]

Agree FrancesHinden.
Keep your same counter to 2-suited overcalls.