Posted 2016-July-07, 21:56
It's definitely a game try, and, as Stephen Tu says, subject to partnership agreement. The 2 ♠ bidder must have extras either in points and/or playing strength to try for game opposite your presumed 5-9 raise with 3+ trump.
By far, the most players these days would be bidding the new suit as a natural bid game try or help suit game try. Both are very similar in that they are asking you to give more weigh to a good holding in the "ask" suit in deciding whether to bid on to game or not. If opener just wanted to be in game on the strength of your raise, then a 2 NT rebid could have been made. The difference between a natural game try and help suit game try is that the help suit game try is showing some weakness in the suit and asks you to bid game with a holding that helps reduce losers in the suit. So with ♠ xxx you should sign off in 3 ♥. But with x, Hx or holding a control in the suit, bidding game is usually right. I think you'll find that most of the time, you'll find that your rebid will be the same no matter which of these two types of game try are used.
There is another possibility in responding to these game trys. If you don't have "help" in the try suit, then, you can bid a concentration of values in another suit if below three of the agreed suit. With ♠ xxx ♥ Qxxx ♦ xx ♣ KQ10x, 3 ♣ would be right after the 2 ♠ rebid.
Opposite a random partner, I'd assume natural/help suit trys and bid accordingly.
A few people play short suit game trys. They show shortness and ask you to bid on if your values are OUTSIDE of the suit bid.
One other point is that many people using game tries define a reraise as a signoff to play. Here that would be a 3 ♥ rebid instead of 2 ♠.