Rocks'n'Diamonds

"override custom artwork: yes" means always override custom artwork.
"override custom artwork: no" means never override custom artwork.
"override custom artwork: auto" means... what? only override custom artwork when it isn't the same as the current artwork? but that would just be the same thing as "yes".
(replace "artwork" with "music" or "sound" as desired)

i've been pondering this for a while (and i swear i made a thread on it, but i can't find it) and i thought i finally had the answer; when i was playing some of the krissz levelsets with my personal custom music enabled, i realized the krissz custom music had definitions for what music to play in the editor, whereas my personal custom music didn't, and so i figured "override custom music: auto" could mean "use your own custom music, unless you have no music defined for a certain situation (e.g. title screen, help menu, editor) in which case use the levelset's custom music (and vice versa)". turns out it does not mean that; setting it to "auto" resulted in no music playing in the editor, just like when i'd set it to "yes"

Shame on me ... this is one of the setup settings that definitely needs an explanation, and the corresponding documentation on this is not "bad", but "non-existing at all".

Older (well, very old) versions of R'n'D only had "yes" and "no" for the "override" option here, plus an additional setting called "auto-override non-CE sets: yes/no", which might have been a bit better to understand (or maybe not).

So here's how it works:

If you select some custom artwork and have the "override" option at "no", it is only used for level sets without artwork.

If you select some custom artwork and have the "override" option at "yes", it will always be used for any level set, regardless of them being defined with or without their own artwork.

If you select some custom artwork and have the "override" option at "auto", it is only used for level sets without artwork for custom game elements (but which might have its own artwork defined for non-custom game elements).

Example:

You have selected the graphics set of the GDash cave collection (named "Boulder Dash").

• If "override" is set to "no", it will be used for "Niko Böhm's Tutorial" (which has no artwork included), but not for "Ncrecc's Tutorial - Ncrtutorial" or Alan Bond's "BD2K3", because these level sets come with their own artwork.
• If "override" is set to "yes", it will be used for "Niko Böhm's Tutorial", "Ncrecc's Tutorial - Ncrtutorial" and "BD2K3" (and any other level set, too). This works perfectly fine for "Niko Böhm's Tutorial" and also "Ncrecc's Tutorial - Ncrtutorial", but not for "BD2K3", because the GDash artwork has no custom artwork defined for custom game elements (and if it would have, it would most likely not fit for BD2K3's custom elements, of course).
• If "override" is set to "auto", it will be used for both "Niko Böhm's Tutorial" and "Ncrecc's Tutorial - Ncrtutorial", but not for "BD2K3" -- because this level set has custom artwork defined for its custom game elements, and no other (foreign) artwork is likely to have matching artwork defined for them.

This means that "auto" might be a good setting to override artwork for any level set that only uses "classic" game elements using your preferred, configured artwork, while level sets with custom artwork for custom game elements (like "BD2K3") can still be played with correct artwork (and without the need to change your setup settings to play them).

This information should be available directly in the game somehow, near this setup option, but currently isn't.