XCOM 2 is a near-endlessly complicated game, full of systems and mechanics that have to be understood and managed if you want to succeed. Of course, with something like this, it’s usually the small stuff that will trip you up, and lead to you failing a mission, or tossing your mouse on the ground in frustration. One of these seemingly simple things that is nonetheless important to understand is how to climb buildings and get onto the roof.
XCOM 2 doesn’t really tell you how to do this, instead expecting you to just know, or scan through the multitude of key bindings to find out. Basically all you have to do to get your troops onto a roof, climbing nearby ladders or other objects, is to zoom out and select the available spot.
To zoom out you just scroll the mouse wheel up, then scroll down to zoom back in and get back to the ground floor. It’s a little backward from what you might be used to doing, but it kind of makes sense in that you are scrolling up to move up to a higher floor, and down to do the opposite.
If your soldier is within walking/running distance of the spot on the roof, you will see the usual blue or yellow outline denoting where they can move. Right click as you normally do and the soldier will do the rest, finding the ladder or other object, and climbing it to reach the roof. From there you can set up some really great ambushes, snipe enemies, or just act as a lookout, as the higher vantage point will really extend your view distance.
To get back down you usually don’t even have to scroll your mouse as XCOM 2 will simply show you the available spots on the ground. Select where you want to go and, once again, the soldier will do the rest.