archive sources: Sined's EFF page
Note (2017-07): this is all b0rked now that shield weights have changed to accommodate melee shield users. Examples, large metal shield is now 10 wt, bronze tower shield is now about 15.
EFF Shields (Endorphin's Floating Friend)
The effectiveness in blocking attacks is determined by the weight of the shield, i.e. a large wall shield will be much harder to knock down than a small wooden shield. As this is the case, it is much harder to successfully float a heavy shield than a light one.
The ability to float a shield is determined by the caster's bonus in magic.methods.physical.binding and the shield weight. The ability to control a shield is determined by the caster's bonus in magic.spells.defensive and the shield weight. Insufficient skill to control a shield will mean that the shield will fail to block attacks, and ability to cast the spell on a given shield does not guarantee that the shield will block efficiently for the caster.
Below is a list of shields and suggested magic.spells.defensive bonuses (compiled from tables by Sekiri and Sined; Kefka's site, and from the current wiki). The first bonus column is what would give a fairly decent block rate with some chance of tms, whereas the second column is closer to maximum effectiveness.
Shields can be ordered at Ug Ogg's Custom armour shop in the Djelian Guard Guildhouse, Djelibeybi. It can be found at the north-east end of Djelibeybi near the Palace. Quality (and cost) varies from inferior, low, medium, high, and premium. With the inclusion of Ephebe as a thriving city and smuggler's maze underground, Klatchian steel tower shields are readily available through random crates that load inside this maze.