So anyway. I've started catching up on some of my email lists for the last week or so (longer in some cases :)) and came across some discussion on one list about oaths, and the idea that just how binding an oath actually is can depend on who the oath is made to. It's not the first time--although it's likely the most glaringly weird example--I've seen some heathens use the innangardh/utgardh (sorry for any misspellings there) thing to justify treating non-heathens differently.
And obviously it's not something I agree with--I can't imagine that your Wyrd would suffer any less because of who you behaved dishonorably toward--but I'm wondering whether there are any stronger sources for this. The main lore-based precedent I've seen cited is the dealings of the Aesir and the giants, specifically the tale where the Aesir contracted with a builder to build a giant-proof wall around Asgard, agreeing to pay him the sun, moon and Freyja if he could complete it within the time limit because they thought he couldn't, turned out he could, Loki got them out of it, yadda yadda yadda. Anyway, I'm looking in Snorri's Edda now, and here's what he says specifically about how that all ended:
And when the builder realized that the work was not going to be completed, then the builder got into a giant rage. But when the Aesir saw for certain that that it was a mountain-giant that they had there, then the oaths were disregarded and they called upon Thor and he came in a trice and the next thing was that Mjollnir was raised aloft.
So that before they knew he was a giant, they had stuck to the letter of the agreement and their efforts to escape giving him payment amounted to going between the lines (probably fair enough since the builder himself had an advantage in his mighty horse that he did not let on to the Aesir about, so that neither party was totally open to start with), but when they found out that he was a giant, all bets were off.
But I don't think that's strictly a matter of one of us/not one of us, and doesn't really indicate that it's acceptable to cheat those who are not in the innangardh. The relationship between the gods and the giants was explicitly one of enmity, not simply of being different tribes--the giants were working toward specifically different, in fact opposing, goals.
So what I'm curious about is whether there is anything else in the lore that might support the us-vs.-them thing that you sometimes see. I mean, it's got to be based on more than just the story I mention above, right?