This issue of the confusion between the story and plot tags has been brought up twice in the past (years ago):
- How should the “story” and “plot” tags be used?, in November 2011 (eventually closed as a duplicate of the later post...)
- Do we need both [plot] and [story]?, in October 2014
- Also semi-related: Should “Story” and “Campaign-development” be merged?, from May 2013
Both prior discussions seem to have been inconclusive, with no clear consensus - resulting in the continuation of the status quo.
T.Sar's answer to the more recent question suggests a theoretical difference between the two tags:
Plot is something that will, or at least, can happen. Your campaign have a plot - the planned events that you want to put the players in.
Story, on the other hand, is something that already happened or is more or less static: your character background, the lore regarding a magic item, the tales regarding the founding of a dungeon, that kind of stuff.
The "Plot" tag should be more about planning stuff, while the story tag would cover telling stuff.
At least, that is how I would use each tag. If this is the way they are being used, that's another matter.
SevenSidedDie's comment on this answer questions whether this hypothetical distinction is how the two tags are actually being used.
In fact, doppelgreener's answer points out that this is not how the tag was being used at the time:
No, we don't need them both, and we should make one a synonym of the other.
Multiple dictionaries define "plot" as primarily meaning "secret scheme", and secondarily meaning "story". We've been using plot in the second sense, which means we're using it exactly as a synonym of story. We can't get much more of a solid synonym than that.
[The other answer] makes a distinction between them that plot is forward-looking narrative and story is backwards-looking narrative. The definitions we're operating on don't make such a distinction though, and neither have the users — both tags are being used both ways.
In fact, since the issue was most recently discussed, the problem has only gotten worse. That theoretical distinction between the ways that the two tags could be used (as T. Sar proposed) is not how the tags have actually been used (as doppelgreener pointed out).
The two tags are very inconsistently and quite interchangeably used. In fact, even the tag info for the two tags doesn't at all make it clear how they're supposed to be used or how they're different from one another.
The story tag info says:
The sequence of events that take place in the fictional environment of a roleplaying game.
The plot tag info says:
The narrative arc of the story cooperatively told by all participants in the RPG, including both planned and unplanned elements.
There seems to be a ton of overlap between these two, and the brief tag info (and nonexistent tag wiki) does not sufficiently differentiate the two tags or really explain how they are used.
Given what a long-standing (and still unresolved) problem this has been, the two tags should be synonymized.
If I had to suggest a direction for the synonymization/merging, I'd suggest we make story a synonym of the main tag plot; the latter seems less generic and thus less likely to be misused.