So, got Arena. Started playing. Found a buckler. It says it gives a negative AC, and it seems to lower my armor when I equip it. Is this right?

Arena works more like AD&D at the time, where armour does the golf thing and is better the lower the number, characters advance through gaining experience by killing enemies rather than levelling up skills, etc. So the shield is adding to your character's protection, yes.

OK, thanks! That confused me, I'm used to Bioware RPGs. (Not sure if Bioware's a bad name on here...)