According to Vetron's Guide to Weapons and Armour, the club has a "2" effectiveness rating.
Clubs have been seen in the series since Ultima I, but only as used by monster types, particularly giants, ettins, and cyclops. It wasn't until Ultima V that the club because a player-usable weapon, and even then it was most commonly found on the bodies of slain enemies, rather than as a purchased item.
Oldest of all bludgeons, and probably of all weapons, is the club. Clubs are crude weapons, but when a blow connects, it often does the trick.