Wielding shield with 0% spell failure?

[Vinven]

Heya.

After filling in much of my Archmage enhancements, I've started putting some spare points into Eldritch Knight for enhanced defenses. I decided on getting the enhancement for shield proficiency after seeing a wizard firewall tank with one. However I don't care for the spell failure chance. I tried reducing it to 0% with inscribed armor, and the medium armor proficiency enhancement, but neither of them work.

Is there a way to reduce shield spell failure that I am not aware of? Is it worth bothering with the enhancement?

[Thalone]

Inscribed Armour is for body slots only and does not apply to shields. You want to get items with Arcane Spell Failure reduction (comes in blue augments too). Multiple items will typically not stack.

The weight of the shield plays a role in how much base ASF there is. Some shields are special and have reduced ASF (e.g., Skyvault is a tower shield with 0% failure).

Also: is there a particular reason you need proficiency? The blocking DR does not need proficiency to work. Additionally, you can cast/scroll Master's Touch to gain proficiency in any shield, though this will not work as a prerequisite for feats or enhancements.

[autochthon]

EK has 10% shield (actually flexible) failure reduction in the spellsword cores, 5% in T2 with shield mastery and 15% in T5 (if you were to go there). The Core + shield Mastery is enough to use heavy shields. Tower shields are pretty much not happening outside of special circumstances (40% base ASF tower shield requiring mithril or a named shield and -10% ASF from augments allowing the 30% available in tree to drop it).