JoeGKushner
Adventurer
Right, but the earlier the divergence in a fictional setting, the lower the amount of canonical material a prospective DM would have to familiarize themselves with. So it's not zero homework by any means - but after that point, there's basically no such thing as canon.
I've decided to toy around with the idea here.
-O
On the other hand, having a greater knowledge of the line, you can bring in elements that were unknown at the time of the original devergance in a different way.
For example, there's a world of difference between just using the characters and elements of the first three Star Wars movies than making changes to those time periods using the expansion of material outside that initial timeline.
Ditto for the Realms.
What if the Shades returned during the Avatar Crisis?
What if the Aboleth Soverignty returned during the Year of Rogue Dragons?