Quick DM Question... (in General)

I searched the Wiki and the FAQ, so you don't need to harass me about my question Ranger.

Will Dispel Magic reduce a ED spell below its base level? For example, when you initially train Protection, it gives you 4 AC. Will Dispel Magic take this value down to zero, or will it leave it at the base level of 4? Sorry for the somewhat noobish question everyone, thanks for the help.

From my meanderings I have found that it completly obliterates the spell in question. Thus a Protection of 4, is reduce to 0. As the spell Fizzles.

That's what I figured, but I wanted a second opinion. Thanks!

It stops it from being cast.

That's a good question! Reducing Protection to Zero would still allow it to cast at (4), but DM stops it casting.