In the Sword Coast Adventurer's Guide (p. 136), the second paragraph of the Swashbuckler rogue's Rakish Audacity feature description reads:
In addition, you don't need advantage on your attack roll to use your Sneak Attack if no creature other than your target is within 5 feet of you. All the other rules for the Sneak Attack class feature still apply to you.
However, in Xanathar's Guide to Everything (p. 47), which reprints the Swashbuckler rogue subclass, the description of the Rakish Audacity feature reads:
You also gain an additional way to use your Sneak Attack; you don't need advantage on the attack roll to use your Sneak Attack against a creature if you are within 5 feet of it, no other creatures are within 5 feet of you, and you don't have disadvantage on the attack roll. All the other rules for Sneak Attack still apply to you.
I can't find any acknowledgement of the text change; I'd imagine that one or the other would have been subject to errata that makes them have the same wording.
Which wording is correct?
EDIT: A continuation of the original question follows, which was based on incorrectly thinking that SCAG was printed after XGtE, and hence wondering if the SCAG text might be an intentional relaxation of the conditions the ability could be used in.
I'm assuming [the SCAG text is correct] since it was printed later, but would like a source.
Additionally, does the SCAG wording mean that the ability can be used with range attacks? I assume that RAI it should not, but I'm having a hard time interpreting "if no creature other than your target is within 5 feet" as meaning that the target must be within 5 feet.
Best Answer
Both are correct, as an official Errata correcting one or the other has not been released.
The Sword Coast Adventurers Guide (SCAG) was officially released in November 2015, while Xanathar's Guide to Everything (XGtA) was released November 2017, making the version in XGtA the most recent official version of the ability. A good number of DM's go with the "most recent printing" rule, or "Whichever book came out most recently is the new official version of the ability", but this is a house-rule, not an official stance as far as I'm aware.
Since there isn't a clear or specific rule that says which version is correct, the best advice I can give is "Ask your DM". I am surprised though, considering how Wizards went out of their way to make sure we knew that the Bladesinger's Extra Attack feature was changing in Tasha's Cauldron of Everything.