Do I have to introduce characters early?

Question: I was wondering whether all major characters have to be introduced in the beginning or fairly early. When is it just too late to introduce an important character?

Answer: The simple answer is no. There are no hard and fast rules about when all the major characters must be introduced.

Obviously, your main character will be introduced fairly soon and usually on the first page, but not always. Some stories start with a preliminary scene before the main character enters. Sometimes too, a major character's influence may be felt throughout a story, even if the character doesn't actually appear until near the climax.

But most of the time, it takes time to introduce everyone, and not everyone can be first in line.

As for "when is too late" to introduce a major character... Well, if he doesn't appear until after the climax, there's not much chance for him to make a big contribution, is there? Perhaps all he can contribute at that point is some evidence as to whether the main character's decision at the climax was the right one.