I've started the game today and am looking forward to it. Incredibly though, I cannot figure out how to interact with players or objects. I've tried using TAB key, right clicking, left clicking, alt- and ctrl- combined with each of those and many other tactics. I know I must be overlooking something incredibly easy, and yet I am not finding it. For example, I walk over to Heodan to check on equipment at the beginning of the game. I believe he wants to talk with me or trade with me, but how do I get that window to engage? I use the tab key and I see various boxes are highlighted. When I hover over one of them, there is a reference to Mechanics, but then I can't do anything more. When I hover over the other boxes, not even a reference to Mechanics. 

 

Would some kind soul please nudge me in the right direction?

Left clicking on a non-hostile NPC should bring up the dialog box if it's available. Have you tried checking your control mapping (bottom option when you hit ESC) to make sure something didn't get messed up in there? Things like moving to a spot, attacking, and interacting with NPCs/Objects should be defaulted to 'Mouse 0'.

Thanks so much for your response. Yes, you are correct. Puzzling that the controls were not set to default, since I just downloaded the game and this was my first time playing. Should be good to go now, though!

you need to point your mouse at their feet (selection circle) .... same for targeting

 

a little later in the game you'll interact with a woman whose feet are .. um .. not touching the ground .. same deal with her; figure out where her feet would be touching the ground

Thanks for taking the time to reply, kickingbird. Oh, I was clicking aplenty on their feet. It turned out, as Sylph suggested, that I mysteriously had no key mapping for key interaction activities. Everything is all better now.