The reason for not accepting new arguments in the 2NC is simple: It is abusive to the AFF to have to respond to new stuff while also responding to the arguments in the 1NR, in the 1AR. whine whine whine. Such excuses are petty, and hardly deserve notice. The whole point of the negative block is to level the playing field between the AFF and the NEG. The AFF has the advantages of the last speech, of infinite preparation time for their case (at home, in class, etc), and they determine just what the debate is about. Meanwhile the NEG may have never even heard of the AFF's case before. The only advantage that the NEG has over the AFF in a round is the negative block, and to limit what the NEG can do with this time, on the grounds that it is abusive to the AFF, is ridiculous. The 2NC is a constructive, and thus, it should be perfectly legitimate for the NEG to make as many new arguments as they want.

That being said, I don't think that New in the 2 is the best idea strategically (unless you are really fast and will completely spread the 1AR, or if there are other special circumstances.) The negative block has 13 minutes of speech time to build up arguments and completely annihilate the AFF position. If done well, the negative block is extremely difficult to recover from in the 1AR. Unless most or all of the NEG arguments are completely blown out of the water by the AFF in the 2AC, a round can be best won by building up and expanding on the arguments that the NEG has already introduced. The judge will put more weight on these arguments that have been built upon and explained, and if the NEG leaves less open to be turned in the round.

For instance, let's say the NEG is winning on a DA and then gets up in the 2NC and reads another one. The AFF then gets up in the 1AR and turns the new DA, and now the first DA is neutralized by the second one, there are no more opportunities to bring up new material, and the judge votes AFF on the other case advantages. The NEG doesn't know what the AFF will hit its arguments with, in the 1AR, if they run new stuff in the 2NC. By dedicating the negative block to stuff that was run in the 1NC, and then not responded to adequately in the 2AC (implying that the AFF doesn't have good response), the NEG has the best chance of facing a 2NR can build on 13 minutes of good arguments that were only weakly responded to in the 1AR. Best of all, by having spent 21 minutes on that same block of material, the NEG has built the best possible wall of opposition to the AFF position, and the arguments have gained far more credibility with judge because of the frequency with which they are mentioned. New arguments in the 2NC can be a waste of valuable speech time, if the AFF has good responses which the NEG hasn't anticipated, when the time could be used to develop winnable arguments.

There are only a few times when new arguments in the 2NC are worthwhile. If everything that the NEG reads in the 1NC falls into an AFF trap, and the AFF gets up in the 2AC with 5 pages of frontlines against all of the arguments that the NEG just made, it might make sense to run something new in the 2NC. It is good to recognize the arguments you think you will win, and the ones that you know you can't win. A good rule of thumb is that, if when entering the negative block it is obvious that the NEG is losing its arguments, the NEG should try something new.

But new arguments in the 2NC can also used strategically to spread out the 1AR. If the 2NC reads 2 new DA's and a Counterplan shell, and then the 1NR goes back to all the arguments in the 1NC and covers them all, the 1AR will almost never be able to cover all of the arguments in the round adequately. The 2NR will then pick up all the arguments that the 1AR missed and win on those. This strategy works best when the NEG is an exceptionally fast team, and the AFF is rather slow. But if the NEG is just going to be reading generic stuff (in the 2NC) that the AFF undoubtedly has resposnes to, on file, then it just isn't worth it.

Another good example of a time where new 2NC arguments would be appropriate would be if the NEG reads a Counterplan in the 1NC and the AFF kills net benefit in the 2AC. It would be a good investment of a couple of minutes of the 2NC to read a new DA that doesn't link to the Counterplan, which the 1NR can then add on as new net benefit to the Counterplan, creating both an additional DA and a CP that the 1AR is going to have to cover.

Unfortunately, too many regions of the country reject new 2NC arguments immediately, with no thought to the justifications for such arguments. Obviously, do what you have to do to win, but don't be scared by the reigning paradigms in your region. I have seen many judges forced, almost against their will, to vote on new 2NC arguments because the new 2NC arguments were legitimate. Keep a set of short "new arguments in the 2NC are legitimate" arguments in your files, to read if the AFF cries abusive. Or, if you think the judge is definitely going to hate your new material, read them before your new argument. But, don't give up…never give up. Fight until every judge allows the NEG to construct whatever arguments they want in the second negative constructive.

Sample "new in the 2 responses" to keep on file:

Observation: New 2NC arguments are legitimate
1. 2NC is a constructive
This is a constructive speech. We can bring up anything that we want.
2. Fairness
The AFF gets two constructive speeches the NEG must be given the same privilege.
3. 2 Negative constructives makes for best debate
By giving the NEG 16 minutes to respond to 16 minutes of AFF constructives, you allow for the most clash, and the most argumentation, which leads to the best, most educational, most interesting, and most challenging debate.
4. The AFF has to try
Unless the AFF has a great response to everything that we read now, and they still run out of time, it is the AFF fault, not ours, that they can't respond to everything. So crying abusive in the 1AR is absolutely unacceptable, a sign that we have won fair and square, and should push your vote towards us, not towards them.
Now let's move on to my first DisAdvantage...