I'm new to the game.

I've seen mentions in various videos (which mostly are old enough that they don't cover the current version) of a 'planet bonus' or that 'the game encourages you to specialize planets'.

I can't find on my planet screens any particular bonus, other than habitability. For three planets I have that all have the same habitability, the production from Industrial is always 12+6, Generator 24, Mineral 19, and Ag 24.

So I'm not seeing (yet?) why I should specialize a planet and build all one type of production district there, and I'm not seeing a reason to prefer one type of production over another for a given planet (other than just balancing overall empire needs).

Does anyone just add districts according to what you're shortest of at the time?

ok this is two planets early in my current game

the farming one allows my to build farms fast/ cheep and get better output... if you click where the farm icon is you can see what other options are there but this world covers my basic food needs pretty nice

the 2nd world is more tricky... yes I would get a bonus to power [and will in fact build a few early] but there are only 5 out of a possible 20 or so thats a waist

I will change this world to urban in order to builds cites [each city unlocks a new build tile] and later on I'll change the world to a science with buildins to match... saving one slot for police and another will be forts (or maybe a shield)

you start with one Planet {most senarios} and that is your capital... a capital is in itself a type of special world so you can't make your capital into say a farming world unless you first move your capital to another world

I finally found what I was looking for, which was where in the UI the planet modifiers are displayed.
My problem was none of my planets except the home world had one, so I didn't recognize that as what I was looking for.

For anyone else, the planet modifier is a circular icon in the lower right corner of the upper left pane. Your Birkenmar Prime planet (study.jpg image) shows it, and I think you were mousing over it to show that it's a 'strong magnetic field' modifier to create that pop-up.