Blocking depends on block strength, max HP, and armor. A deficit in any stat will make blocking ineffective.

Shields were rebalanced over the early days, bronze buckler is no longer a god shield. Parrying now has a huge stamina cost, so it's a tactical choice rather than the default goal of blocking.

For the most part, a proper tier shield and full food buff can block any regular enemy. One star enemies hit too hard for flat blocking, and two star enemies hit WAY too hard for shields at all. Keep bonemass power on hand at all times to deal with elite enemies, the massive damage reduction also boosts blocking.