c) New lines of attack based on documents submitted during first-instance proceedings – not admitted 

In T 256/17 the board had to decide whether to admit two new lines of attack submitted against claim 1 of the patent on the basis of a lack of inventive step which the appellant (opponent) had filed in response to the respondent's reply. Both lines of attack were based on documents submitted during the first-instance proceedings, but one of them combined for the first time two documents previously discussed as the closest prior art and the other, starting from a known combination, argued on the basis of a different technical problem. The appellant gave no reasons for first raising these objections after having filed the statement of grounds of appeal, and the board could no reason for this either. It pointed out that, by acting this way, the appellant had prevented the respondent from reacting to the attack during the opposition proceedings and the opposition division from deciding on the matter. With the late submission the appellant had confronted the board and the respondent with a fresh case, which was contrary to the very aim of appeal proceedings, which was to review the decision under appeal in a judicial manner (see Art. 12(2) RPBA 2020). The board thus decided to exercise its discretion not to admit the new lines of attack under Art. 12(4) RPBA 2007 in conjunction with Art. 12(2) RPBA 2007 (essentially corresponding to Art. 12(3) RPBA 2020) and Art. 25(2) RPBA 2020 and under Art. 13(1) RPBA 2020 in conjunction with Art. 25(1) RPBA 2020).