In the tutorial I get stuck at a point where you're supposed to execute a guard from behind with a silenced pistol. I have the pistol and I have the silencer, but when I try to Alt+Right Click the guard, my agent does nothing. Did I screw something up?

Have you tried getting close to the guard from behind before Alt+Right clicking? Also, you have to have the pistol and silencer as your active weapon.

Just above the agent's portrait on the bottom left there is a weapon icon. If you click on that you can select which weapon to wield. The icon needs to be red, which will correspond with you seeing the pistol in your agent's hand.

Also, the game might distinguish between left alt and right alt, so make sure you try both. It's possible that there are alternative keys for assassinate as well. I think I read somewhere that you can Shift+right click as well, though I haven't tried it myself.

The assassinate thing is tricky for some reason. I never could do it in the tutorial either for some reason. I only figured it out later. I think my problem was that I either didn't have a weapon drawn, or I did but it wasn't the pistol.

Sounds like it's the old Linux problem of Alt being the default key for messing around with the window size/position. Left Alt+Left Shift+Right click used to work for me, but then I changed the window-key from Alt to Super (Windows) so I could use Alt+Right click even for force-using stuff like ziplines, terminals and hardwiring.

ODDity wrote:
your window manager will have a way to change the key to move/resize/menu key from Alt, to "super (win)".. In cinnamon for example it's in system settings -> windows -> behaviour tab and the the sepcial key to move / resize there is selected.. whatever you're using should have similar.

I have to do this every time on a fresh install because I use Blender which makes heavy use of alt + RMB.

EDIT: I just paid some extra attention to the thread title. You can totally complete the tutorial without assassinating that policeman. You can rush through the tutorial without following all of the instructions to the letter, killing anyone in your way, or killing no one at all. But knowing how to assassinate is usually very beneficial. They made it a bit easier in the latest update, increasing the angle at which the agent is considered 'behind the target'. While in the same update introducing a bug which makes the assassin sometimes run back and forth a few times before heading off towards the target.

KDE user. To force stealth shot, press and hold Meta(aka Windows key)+Alt together instead of just Alt.