A few weeks ago someone in the newsgroup posted how he got an intrinsic
value for increased damage up to something like +74 via eating rings (on his
way to killing the Riders a zillion times for maximum score--he wanted to be
sure to kill them in a single hit each time so that his use of keystroke
macros wouldn't get out of sync by extended combat). Make it moderately
difficult to get beyond +20 and impossible to get past +40 for corresponding
attribute when eating rings of increase damage, increase accuracy, and
protection. Since you could also wear a pair of +7 rings you can still get
an awfully high total, but it won't be unlimited any more and most people
willing and able to go to such extreme lengths would undoubtedly prefer to
be wearing other types of rings.