At a recent game, a character confirmed a critical hit with a natural 20 and there was a brief discussion whether natural 1s and natural 20s auto failed or auto succeeded (respectively) to confirm critical hits.
The ending result was that, the Players Handbook says attack roll so it utilized the normal attack roll rules (which includes 1&20 auto-fail/auto-success).
From the srd:
Automatic Misses and Hits A natural 1 (the d20 comes up 1) on the attack roll is always a miss. A natural 20 (the d20 comes up 20) is always a hit. A natural 20 is also a threat—a possible critical hit.
To find out if it’s a critical hit, you immediately make a critical roll—another attack roll with all the same modifiers as the attack roll you just made.
I recall in the past reading differently but could not find anything in brief look-over including the MainFAQ. Any other citations we missed that might make this more clear/compelling one way or the other?