Activity

How bad is it to have something new show up in the climax and surprise people? For instance, a few of my climaxes involve my characters, for lack of a better word, ‘unlocking’ new powers they didn’t have before, which help resolve the problem. Everyone says the climax should be well-foreshadowed and not come out of nowhere, or the audience might feel cheated, even think of it as a deus ex machina. Any suggestions to help balance the desire for surprise and the need to build up to the solution?