1NT doubled

Answer 1

It takes 3 passes in a row to set the contract and pass out the hand. A double counts as a bid, so the 3 players following you all get the option to bid or pass.

Your partner has the option to bid (we play a double in this position for takeout, so my partner would be obligated to bid) or the opener's partner can redouble or run to another suit after your double if he/she so chooses.

I play duplicate, but the rule on play is the same in rubber bridge.