I was curious what tech I need to focus on to get terraforming? I see a lot of planets that require it.

Focus Research in the BioTech tech field and you have a chance to discover Terraforming.

Once you have it researched, you can go to each colonized planet that isn't your races ideal (your homeworld is the ideal type) and select to terraform.

The setting is in the top-left panel via the Ecology Control setting. Set it to Terraform to begin the process.

Thank you very much! Horizon has become my mainstay 4X game of choice, beside MOO 2 of course.

1. The UI is easy to navigate
2. THERE'S NO SPACE LANES!
3. The races are all very unique
4. The background music is spot on
5. Creating ships IS NOT A CHORE!
6. And the side quests are a lot of fun

It's great to hear you are enjoying the game! And the feedback is always very helpful on which features stand out.

Yeah, I tried getting into Stellaris but it's just Crusader Kings in Space.

Fully agree!

Is terraforming a super important thing to research fast btw?

Terraforming planets can be very costly early on so I would say it's better to look for good habitable planets to colonize. But once you can't expand or there aren't good planets you can reach then Terraforming is the next best option.

I have to admit that i barely ever use it. There are usually enought good plantes to colonize. By the time i should/could terraform, i am usually in wars with other Empires.

Note: i guess i would use it more often if the map was bigger/the expansion phase lasted longer and there were less good planets (i know i could change it in the starting settings which is what i may do in my next game).