The teddy bear item adds 15% block chance per stack. This means that at 7 stacks, you'll hit 100+% block chance. Unlike the Lens-Maker's Glasses, the additional sentence at the end has me wondering what it means.
It says "Unaffected by Luck". But if you block all damage 100% of the time, wouldn't it render the rest of the game pointless since you can no longer take damage?