Sometimes, just sometimes I start a game and i start with 2 settlers. (only happens at chieftan difficulty). Does anyone know how this happens
I call this a 'double yolk' game, like when you crack open an egg and find a bonus golden treasure inside is hid (credit JRRT). In other places in this forum, people claimed that it happens more often when you play under the colors of Rome/Russia, but i think that is a myth, a civperstition. Another civperstition is that this happens only when playing Cheiftan level. I believe it can happen at any level.
The basic reason it happens is the same mechanism which determines how many technologies you start the game with. You have probably noticed that you start the game sometimes with only Roads and Mining. Other times, you start with R+M, plus Alphabet, Pottery and Ceremonial Burial. When you start with a double yolk, that extra Settler is taking the place of an extra technology you would have started with otherwise.
Why do extra techs and extra Settys happen? It is a function of your starting square. When a game starts fresh, the AI calculates the total food production of the area around the square where it has plopped you down into the world. If it's a pleasant landscape, full of grass and rivers and plains, then your chance of extras is small. But if the AI starts you in an area hostile to growth, it compensates by awarding you with bonus techs and maybe a Setty if you are lucky.
But are you really lucky, when you get a double yolk? I say no. When you get starting bonuses, that means you are going to have a more difficult time building up your civ, because the landscape is inhospitable. You typically get your first earned tech long before you can use it anyway, so the benefit of fewer bonuses is a nicer homeland where you can found your second city much faster and that, in turn, brings in new technology at double the rate. The one exception is Alphabet, which is a priceless advantage to start with. I gladly start next to swamps, if it means a free Alphabet.
Your second question...
Can I make it happen every time?
Short answer: No. If you desire a double yolk game, the only thing you can do is start-quit-start-quit until it happens. You can not use any ploy to make sure you get 2 Settys every time, without fail. But, there is a way to slightly bend the probability of getting a double yolk. If you can start on the nastiest landscape possible, then your chances of a double yolk game game go up. Choose to customize your planet before beginning a new game, and pick Small-Wet-Warm-Old (SWWO) or Small-Dry-Cool-Old (SDCO). "Small" means you are more likely to start on an island. WW means swamps and jungles proliferate. DC means more deserts and snowy squares. And "Old" means more hills and mountains. All at the expense of a potential plains or grassland.
But would you really want to grow up in a place like that? Yes, the same nasty climate conditions would also hobble your rivals, so no disadvantage there. Surely salmon are brave, but most fish say: "hey, why swim upstream when we can do it right here on the reef?"
