Can a rogue, druid, or cleric use Shield Bash without penalty?

Question

Originally I was going to ask, "Can a rogue or druid use Shield Bash", but the answer seemed obvious: "Yes, why not?"

The question then is whether a rogue or a druid can use Shield Bash without the apparent -4 penalty due to non-proficiency. One may think that even though the weapon proficiencies of a rogue or a druid may not include light/heavy shield in their weapon proficiencies list, the fact that they have Shield Proficiency entitles them this proficiency.

But what about a cleric who is explicitly stated to be proficient in simple weapons only? As you'd know, both types of shields are treated as martial weapons for a Shield Bash maneuver..

So, is there any clear wording to this anywhere? The question would be for 3.5e and PF both; although I suspect there'd be any difference for this.

Answer 1

Everybody needs a martial weapon proficiency

The shield bash rules say this (emphasis mine):

You can bash an opponent with a light shield or heavy shield, using it as an off-hand weapon. See Table: Weapons for the damage dealt by a shield bash. Used this way, a shield is a martial bludgeoning weapon. For the purpose of penalties on attack rolls, treat a heavy shield as a one-handed weapon and a light shield as a light weapon. If you use your shield as a weapon, you lose its AC bonus until your next action (usually until the next round). An enhancement bonus on a shield does not improve the effectiveness of a shield bash made with it, but the shield can be made into a magic weapon in its own right

Shield proficiency says this:

Benefit You can use a shield and take only the standard penalties.

Normal When you are using a shield with which you are not proficient, you take the shield’s armor check penalty on attack rolls and on all skill checks that involve moving, including Ride checks.

Shield proficiency doesn't give you any kind of weapon proficiency with shields. It gives you the ability to use the shield and not take the armor check penalty. In order to not take a penalty for using a shield bash, you need that martial weapon proficiency. Classes that give you all martial weapons take care of that pretty easily, like a level of Fighter (or Radiant Servant of Pelor if you're a Cleric).

What about "Simple Weapons Only"?

The other classes you mentioned actually have a list of what they're proficient in, the Cleric's "simple weapons only" is just shorthand for a list that has every single simple weapon on it. It doesn't mean that Shield Proficiency works differently for Clerics than it does for everybody else.

It's also worth noting that the Cleric says "all simple weapons", not "only simple weapons". It's not a special rule or exclusion, it's just a shorter way of saying it than listing every simple weapon.

Pathfinder - The Same

From looking around, this appears to be the same in Pathfinder. The shield bash rules are basically the same, the shield proficiency rules are worded a bit differently but don't affect this, and James Jacobs (Creative Director at Paizo) agrees.

In fact, the Paizo FAQ states clearly that shield proficiency != weapon proficiency with shields.

Answer 2

Light and heavy shields, and their spiked variants, are all classified as martial weapons. There are classes like the samurai which gain proficiency with martial weapons but not with shields; and classes like the cleric that gain proficiency with shields but not with martial weapons. The magic item rules draw a clear distinction between "shield enhancements" and "weapon enhancements" and make clear that light/heavy shields can have both but they are separate tracks -- a heavy shield can have up to 10 enhancements as a "shield" at the same time as having up to another 10 enhancements as a "weapon."

Under these circumstances, I think it completely valid to interpret the term "shield" used without further qualification as referring only to its defensive capacity, as Tridus suggested was clarified in Pathfinder; certainly its usage in 3.5 suggests this without necessarily stating it outright. I will admit at least one anomaly, though; the "bashing" enhancement is categorized as a "shield" enhancement when it seems much more appropriately a "weapon" enhancement.

Finally, as a persuasive if not authoritative point we shouldn't want to interpret it the other way; if you buy into the "Tier" system you shouldn't be looking to interpret ambiguous points in a way that increases the supposed disparity between the upper and lower tiers if you don't absolutely have to. A general proficiency with "martial weapons" gives a fighter proficiency with a number of extremely useful secondary weapons, including various shields and armor spikes, that clerics -- even those proficient with a single martial/exotic weapon through domain powers, spells, or feat selection -- should not have.