This question is in regards to how do we wish to start the game. The discussion thread is HERE (http://forums.civfanatics.com/showthread.php?t=146610).
The choices are:
Play Now,
Custom Game,
No, I will not play; I hate Civ!,
Abstain

Note: choosing option three might result in a tar and feathering.

-the Wolf

I'm guessing play now is all random and custom game lets you customize it.

A good guess or no?

I'm guessing play now is all random and custom game lets you customize it.

A good guess or no?

No, the options in the thread are the options from Play Now and are also in Custom Game, there are more options in custom game such as city culture flipping or permanent peace/war.

-the Wolf

Custom game has a lot of extra options:

You can choose what leader to play.
You can give AI's random leader traits instead of using the built-in ones
You can have specific opponents
More map options
Built-in support for some of the variants (one city challenge, which doesn't let you build settlers for example. Or how about always war and always peace?)
Selection of enabled victory conditions

It's Custom-Game for me with a few more opponents than in play now and a few other adjustments... Random leader traits would be cool, IMHO