Liversidge, on 2016-June-17, 04:12, said:
Partner had 11 HCP and four clubs (Axxx). We made 5 clubs. I made an elementary error assuming that my club bid was forcing (I remembered reding somewhere that a new suit at the 3 level is forcing) but afterwards was advised by an experienced player that this doesn't apply in this situation. I assume that's because we were competing, and also because partner had bid No Trumps, but would appreciate confirmation of this.
A new suit at the three lever is usually forcing in a constructive auction, i.e no opposition bidding. There are one or two exceptions, such as 1S-1NT-2S (or 2H/D)-3C. In this sequence the 1NT bidder is showing a weakish hand with long clubs, e.g X xx Qxx Kxxxxxx. When opponents are bidding, especially if they have opened, such rules go out of the window and new suits are often just an attempt to find a safe spot. In such cases cue bids of oppo's suit are used to show strength. However, as usual in bridge there are no hard and fast rules; you have to use your logic and judgment. For example, if an experienced partner introduces a new suit at a high level you sometimes have to ask yourself whether it can realistically be an attempt to play there. For example, if you overcall 2H and partner, who has previously passed, competes at some stage with 2C it is unlikely that he holds just lots of clubs as if so he would have bid them earlier. He is more likely showing a heart fit and a good club holding, such as X Kxxx xx AKxxxx. This information could be very helpful when judging to pass/double/bid on over oppo's 4S bid. Of course, this requires your partner to be a good player and one who trusts you tou make the correct inference.