Learn English – word to describe words that can be spelled different ways

The word you could be looking for is variant

Definition:

1 obsolete : variable

2 : manifesting variety, deviation, or disagreement

3 : varying usually slightly from the standard form

(examples) variant readings; variant spellings

Also, from google search:

Perhaps...

Role playing games offer a multi-faceted experience.

I think facet is a good word here; as it describes one aspect (of many) of a thing, it maintains the singularity of the experience.

EDIT: In reading a recent article by Alan Jacobs, a literature professor, about the cumulative impact literature can have on a person, I came across an expression that may be useful in this context. Here is the passage:

I’ll repeat here, with some emendations, something that I wrote to a friend last night. For most people literature has limited power to do character-shaping because of the limited range of ways it involves the person. (There are of course exceptions to this rule — I think of William Cobbett, for instance, whose whole life was, according to his own account, altered by reading Jonathan Swift. But even then I can’t help thinking that that could only happen because a whole range of complex experiences had prepared him to receive precisely what Swift had to say.)

Various forms of ritual enactment — Yoni Appelbaum is working on some of these matters in his dissertation-in-progress, and I put the point this way after corresponding with him — seem to me to have much greater power because (a) they engage our sensorium more completely and (b) they benefit from repetition.

Kinda wordy and high brow, but it seems that the expression is being used to express the variety of ways in which an experience reaches us.