Drafting

To make a soldier select a colonist and press the button with 2 crossed swords (image needed), unlike a colonist a soldier can be precisely controlled as in deciding where he/she shall stand, what target to fire upon and so on.

To catch a traveler or other persons a soldier is needed, select the soldier and right click the desired captive and select "arrest <name>" from the menu.

If a colonist haves a mental breakdown a soldier can be used to arrest the person again, which will make him/her a "standard" prisoner again.

A soldier can be combat trained by having him/her attacking a Dumping area, this will increase the chance of hitting a target, be aware that if the training is too long the soldier will have a mental breakdown due to extreme hunger and sleep deprivation, to prevent this switch the soldier back to be a colonist by clicking the sword button again.