question on sucess/failure rates

[quarague]

For spellcasting your failure rate is bounded below by 5% (or 0% if you have advanced spell casting) and most characters reach these limits for most spells at sufficiently high levels.
For melee and ranged attacks success rates are capped at 90% ?? but in practice most characters don't actually hit this threshhold, at least not for monsters where it would be interesting.
Is there a bound for rods/staves/wands/artifacts? Your success rate is influenced by your characters innate device rating and by char level, anything else? Spellcasting stat? How about warriors? Do these 4 item classes use the same game mechanic or are there differences?
Recently found a rod of healing with a HT Paladin at char level 45 or so, he only got a little under 90% success rate with it, so it seemed strictly inferior to just casting the heal spell. Would have been a great find for a warrior or arcane caster though.

[Pete Mack]

There is no technical bound to device use, but the practical bound is ~4% failure for --Teleport Other and other low level magic devices.