Multi league playoffs
 

I have set up a fictional game with 8 different leagues. How do I set up playoffs involving the winners of each of those leagues? Thanks for your help.

If they are separate leagues (and not subleagues under one league) you need to set up an association between the leagues and then set up association playoffs. See here: Out of the Park Baseball Manual

Let me forewarn you though. I have not set up an 8 league playoff, but I'm assuming that you will be able to have the 8 league champs meet under this association playoff format. That will likely work ok.

However, if you try to get any more complicated than that, you often get a game crash. I've tried, for instance 2 teams from one league, and 1 each from two other leagues (4 total teams) and it crashes. The game can't seem to handle odd combinations. Even 2 from each of your 8 leagues (16 total) probably will freeze the game. Keep it simple. Keep your game saved frequently so you don't suffer a crash that you can't recover from. OOTP 13 was the first version with associations and associations still had bugs even after the final update.