Newbie question regarding starting techs

[beetz]

Hi I've just confused myself. I've been trying to get into civ and had a few games with Alexander, I'm pretty sure he don't start with agriculture. I just installed the BUG mod as per many recommendations and started a new game and Alex seems to start with Agriculture! on a slightly different looking tech tree? afaik my previous games were all on the latest build 319 so can someone explain whats happened? thank you!

 

[JujuLautre]

You are playing under noble, at a level at which you get free techs.

 

[beetz]

oh no I'll need to restart! BUG must have defaulted all my settings inc the difficulty. Many thanks Juju for a prompt answer!