1 : to play one's hand as dealt in draw poker without drawing
2 : to oppose or resist change
It's extremely satisfying when the phonetic spelling exactly matches the original, as though the word hides nothing. It is what it is. I had a boss once who used to hate that phrase. It is what it is, he would say, I hate that. Of course it is what it is—what else could it be? I didn't know how to explain to him that often times things have indefinite interpretations; I was so envious of the simplicity of his thought. I didn't want to destroy it.
I use metaphors regarding a dealt hand of cards quite often, mostly in describing people who are negative. My point with this metaphor is usually to suggest we are all handed a set of circumstances and forced to make due. Realistically speaking, there's always going to be someone with a better hand and someone with a worse hand in any given moment. This thought is extremely grounding for me. Relativity. But I suppose this doesn't satisfy everyone.
STAND PAT seems to suggest two ideas:
1) accepting circumstances, and
2) resisting change
These two ideas are not the same thing, nor to they need to exist symbiotically, though they could. You can accept circumstances without resisting change—maybe you do have a good hand. If it ain't broke, don't fix it, right? And if you resist change, it certainly doesn't mean you're accepting circumstances. It usually just means you're afraid of change and, henceforth, stuck with your circumstances by default. On the other hand, if you resist change long enough, you may eventually realize you accept the circumstances.
So, while STAND PAT is phonetically clear cut, the meaning is complicated. The word began at the poker table and segued into a life metaphor, contorting itself a bit along the way. Perhaps its complexity reflects the difficulty of the decision making process. There is a very thin line between content and complacent—you are lucky if you choose not to see it.