Blocking Mechanics

Blocking
Block is a potent defense that is a chance of negating the damage of certain attacks entirely. In the case of the assassin skill claw block the chance to block is determined solely by skill soft level. In the case of normal blocking with a shield the chance to block is based on solely 3 particular stats.

Both forms of block are well known for being able to stop any melee attack as well as arrows. Claw block is well known for stopping any spell with exception to damage per frame effects that are damage over time. Not so well known, however, is the fact that normal block can negate the damage of certain spells as well. While the list of spells normal block can stop is no where near as large as claw block's it still does not change the fact there's certain spell attacks that normal block will protect you from.

Normal Block Chance Formula
[Actual Chance to Block] = [Base Chance to Block]*([dexterity-15]/[character level * 2])

Your soft stat figure for dexterity is the number used for the calculation. The simple way Base Chance to Block is calculated by taking your listed chance to block on your shield and then adding whatever increased blocking chance mods you can find on the rest of your armor, weapon, skills (such as holy shield), and charms. In the case your shield lists a 75% chance to block that may not be accurate since the chance to block display is hard coded to list any chance to block value above 75% as only 75% (thus a shield that should be listing 105% chance to block will only list 75%). In the case the shield lists a 75% chance to block figure out what the shield base item has for chance to block without any increased block chance on the shield then add the all the increased block chance on the entirety of your gear and skills. One more note about the formula is that if your actual chance to block gets above 75% it gets capped down to 75%.

Myths about Blocking
Some odd ideas float around for what can affect your chance to block. This section's intent is destroy such incorrect delusions. - Baerk Konnevala 16:08, 17 December 2008 (UTC)
 * 1) Enemy level and AR affects your chance to block. These two factors affect your chance to be hit in the AR vs. Defense calculation. They have absolutely nothing to do with actually affecting your chance to block. An enemy with high AR/level just simply triggers your chance to block more often since it passes the AR vs. Defense check more often.
 * 2) Faster Block Rate improves your block chance. Reality is while the mod is block related it has absolutely nothing to do with block chance.
 * 3) If you are already in middle of a blocking animation you can't block again until the blocking animation is over. That is blatantly incorrect. Reality is your chance to block can trigger any number of times during any blocking, attacking, or walking animation.
 * 4) Claw Block drops completely while running. The reality is when you are moving in running mode your actual chance to block gets divided by 3 and capped to an upper limit of 25% chance to block. This running blocking penalty applies to both normal blocking and claw block. The penalty also applies to claw block while walking but it does not also apply to normal blocking while walking. The original author of this article has personally seen claw block trigger while running.The author has also seen though cases where there's an erractic bug that makes claw block drop completely while moving that does not always trigger. The conditions that allow it to work at 1/3rd strength or drop completely are unknown at this time.