Gamebanshee's walkthrough for Eye of the Beholder 1 sees the game's Luck Stone Medallions as worthless, but this is one of the few cases where I think they may be wrong. My suspicion is that this magic item gives +1 to all your saving throws, which would be a completely invisible stat. (All Seeing Eye doesn't display invisible stats, of course.)

Can anyone confirm my suspicions?

Good luck testing that.

Of course, I see your point. :)

(Still, I was wondering if it was possible for someone to examine the game code and, if they understood what they were seeing, tell from that. Yeah, it's a long shot.)