House Rule Dep't: Shields, splinters

During session 3 (report upcoming), I suggested we use the "Shields Shall Be Splintered" rule as presented in Fight On! 'zine issue 2. 

Basically, if you're using a shield, in addition to the AC bonus (-1) you also have the option, when hit, of allowing your shield to be destroyed instead of taking the damage yourself. 

Nick immediately had a question that I don't think was addressed in that Fight On! article. He wanted to know if you had to declare your "shield sacrifice" before damage was rolled. We decided, yes, you did, that made it more interesting, more of a gamble. And when we it came up in the game (as it did several times that session), of course we rolled (hypothetical) damage after a shield was splintered, just to see what the damage "would have been", like, were they gonna roll just a "1" anyway?

Another question about this house rule that came up during our game was, what happens when you've been hit by someone (or something) who rolled a natural 20 (a critical hit)? In those cases, should it really be just as easy to evoke this "shields shall be splintered" rule and take no damage? During the session, we decided that would be unfair to person who rolled the crit, and made an ad hoc decision that there was only a 50/50 chance that the shield could take the hit and absorb the damage.

Thinking about it now, I've come up with a more complex solution, that also makes the special shield rule a bit less powerful vs. crits. How 'bout the attacker has to roll again to hit (a "confirmation roll" in 3e as I recall), and if they fail, the shield-splintering rule works as advertised. If they hit, they do normal damage (no roll on the Arduin critical hit chart, which we've been using in lieu of double damage), but the shield in question is also destroyed. And if they manage to roll another 20, it's a crit hit as usual, no damage to the shield however. Oh, and if they get a 1 on this second roll it's just a normal miss, not a fumble. Sound good? [Later edit: this IS what we decided, not the following.]

Or (I just thought of this) a much simpler additional rule re: crits would be that you CAN declare your shield is being splintered vs. a crit, and it always works (no 50/50 roll or "confirmation roll" or anything), BUT you also lose your next action as well as your shield. So the nat-20-rolling attacker gets a benefit, but you do too. 

I guess we'll decide next session. I'll also have to figure out just how many shields an adventurer can carry...