Cover

Cover in RimWorld can be found in five ways: Rubble, Sandbags, Walls, the Saguaro cactus and animals.

Rubble

Rubble is littered all over the map and will be used by attackers to gain an advantage over you. You can also use rubble for protection, but the random rubble placement is unlikely to favour you. so it's advisable to use it as a last resort

Rubble in combination with a dumping area can easily give a turret some extra protection, for free! First designate a dumping area where you want your turret to be, then mark 16 rocks to be hauled to the area, when it is filed sell the dumping area and mark the middle 4 rocks to be hauled again but to another dumping area (designate a new area somewhere if you must), then build a turret inside the resulting square of rocks.

SandBags

Sandbags are the easiest and cheapest method of protection. U shapes are good for one character to hide in. Zigzag patterns will allow multiple characters to cover close together, which is handy if you want to focus fire on a few attackers.

Sandbags enclosing a turret make a great attack point But keep the turret repaired, as it will explode when destroyed and can damaged nearby characters.

Walls

Walls can be used as cover as well. Characters will lean around them to shoot. Three wall blocks placed diagonally make a great sniper nest. Natural walls work in the same way.

Saguaro cactus

It's a large tree like cactus with 2 branches, see this page for a picture.

Animals

A last resort to cover if you have nothing else can be animal(s), by having animal(s) between your colonist(s) and the attackers, they can actually work as a makeshift cover by being hit instead of your colonists. (I learned this from personal experience, when a squirrel got in the crossfire and got hit from a raiders M-24 bullet, and instantly died which means the squirrel was a one time cover).

Not Cover

To minimize confusion, see this page No Cover.