<p>Related, but old and not on GD: <a href="https://meta.stackexchange.com/questions/107105/is-game-development-no-longer-relevant-on-so-due-to-the-creation-of-game-dev-se">Is game development no longer relevant on SO due to the creation of Game Dev SE?</a></p>

<p>I'm unclear when, or even <strong>if</strong> we should be trying to migrate on-topic questions from StackOverflow to GameDev.SE. Migrating on-topic questions, that game developers are more equipped to answer than other programmers, is good for the ecosystem here and advertises the existence of this site.</p>

<p>When I tried to migrate this question, I got in to a bit of a comment war: <a href="https://stackoverflow.com/questions/17479255/how-to-know-if-the-player-is-signed-in">How to know if the player is signed in?</a>. The OP eventually cross-posted and got 8 votes, and an accepted answer with 7 votes: <a href="https://gamedev.stackexchange.com/questions/58616/how-to-know-if-the-player-is-signed-in/58618?noredirect=1#58618">How to know if the player is signed in?</a></p>

<p>I also flagged this for migration: <a href="https://stackoverflow.com/questions/17455038/parallax-background-resizing">https://stackoverflow.com/questions/17455038/parallax-background-resizing</a>. But the migration was declined: "This isn't off-topic here".</p>

<p>If that's a reasonable rejection reason, is there ever a case where a question is off-topic on SO but on-topic here?</p>

<p>Where is the line?</p>