Q:

What can I do in Rimworld after getting the basics set up?

I've started playing Rimworld, and I'm finding it interesting, but I've run out of ideas for what I should do next. So far I've only got 3 colonists, I've setup housing for all of them, a mess hall, a trading beacon and power etc.
What I don't know is how to proceed from here. I can research, but what are some short term objectives I can aim for while this is happening? What are some longer term objectives?
Maybe another important thing is how can I get more colonists? I've read that I can buy slaves, or capture enemies, but I've not been attacked and the only slaver I saw came before I had a trading setup. Should I capture visitors perhaps?

A:

You're off to a good start next I'd get some defenses up, turrets and sandbags to be more specific. This will help with raider waves.
Which brings us to our next part: getting more people.
You can get people in 5 ways right now.

People will wander in and just join up no questions asked
An escape pod will crash and you will have to rescue the person and convince them to join
When fighting raiders, randomly the killing hit won't kill them only knock them unconscious. When this happens you have the ability to capture them
The same can be done for visitors
The same can be done for the people in cryo-sleep pods. A warning about this one though those pods are guarded by some hard to kill and hard hitting enemies open at your own risk

When you capture anyone you need to have prisoners beds set up for them to sleep in. I usually set these up away from my main colony just in case one breaks out. You then need to have a warden "try to recruit them" your chances are better if the person is not injured and well fed.
As from where to go from there you could outfit people with bionic parts, set up different productions to earn lots of sliver or build a rocket and escape the planet.

