There are a couple of different additional points I'd add for each of these cases:
There can be situations where someone is "in" or "out" and thus this can be used as a way of determining if someone doesn't want to play. "Are you out now?" would be a way to ask if someone doesn't want to play. There is also the connotation around one's sexual orientation. These are both cases where someone may say, "I'm out!" and it isn't about being outdoors/outside at all.
While there is the common view of not being inside of a building, there can also be a situation where one may be going to visit a friend and be asked, "Are you outside?" that is in reference to being outside of the person's residence at that point in time. This is rather specific to the proximity of the building is the point I'd stress here.
Alternatively, you could be leaving a club or airport and ask someone, "Is there a taxi outside?" which is in reference to the doors of the building as chances are there are numerous taxis driving around the city but your interest is in one's near the building that you could use to get to your next destination.