-% Target Defense reduces target defense by a percentage of the total when calculating chance to hit for melee and missile attacks. Reducing target defense is equivalent to increasing Attack Rating, multiplying it by 100/(100 - % Target Defense). For example, -50% is equivalent to multiplying AR by 2 (100/(100-50) ), while a combination of +200% AR (*3) and -50% (*2) is equivalent to +500% AR (so -50% itself is equivalent to +300% AR in this case).
- It applies only to attacks made by the user, including Blade Shield.
- Any bonus on a weapon applies only to attacks (including Dragon Talon, Dragon Tail and Dragon Flight) made using that weapon. 
- Defense reduction is halved (if -100% is supplied, only -50% is effectively applied) against the following:
- Defense cannot be reduced below 0, so < -100% is redundant against anything other than the above, and < -200% is always redundant. < -150% is beyond reach in the unmodified game. 
- Chance to hit displayed by character screen when cursor is over Attack Rating field does not take it into account.