Vanguard Shield (3.5e Equipment)
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In the hands of a typical warrior, a vanguard shield functions as a heavy steel shield (Shield Bonus +2, Maximum Dex Bonus --, Armor Check Penalty -2, Arcane Spell Failure 15%).
If the warrior has the Exotic Weapon Proficiency (Vanguard Shield) feat, however, it becomes much more interesting. The warrior is now able to use the shield to defend against combat maneuvers such as disarming, sundering, or tripping attempts, granting its shield bonus (and any associated enhancement bonus) to the defensive check. Additionally, the vanguard shield provides a +4 circumstance bonus on any bull rush and overrun attacks made with the shield. Beyond that, the sharpened edges of the shield can be used to make attacks much like a spiked shield, including being able to be enchanted separately as a weapon. Without the Exotic Weapon Proficiency feat, however, the vanguard shield is just an ordinary heavy spiked shield that lacks any of the secondary perks mentioned here.