For spells, we round down right?

[SangoProduction]

I assume so, based on most spells I've seen discussed, but here's the situation: I'm planning on using Insubstantial Armor, which turns armor into a insubstantial shield with AC value of +1 per 3 levels.
If I set my caster level to 1 (which I think is the minimum), does that mean, it simply makes the armor insubstantial?

[Vaz]

Whatbook is this from, i've not heard of it.

You cannot cast a,spell unless you have a caster level required to castt the minimum. So, assuming it is a 2nd level Sorcerer/Wizard Spell, it would need Caster Level 4 on Sorcerer Casting and level 3 minimum on Wizard casting.

But yes. It does in such events usually say 'to a minimum of...' however.

[SangoProduction]

Ah, I didn't know about that minimum caster level thing. Thanks. The spell should be from spell compendium.
EDIT: No, it's from Spells and Magic.

[Kelb_Panthera]

Your interpretation is likely correct. In most things the game calls for you to round down. Most, if not all, spells specifically call out that you should round down in 1st party sources.

[MesiDoomstalker]

Your interpretation is likely correct. In most things the game calls for you to round down. Most, if not all, spells specifically call out that you should round down in 1st party sources.

Additionally, most also have a minimum value listed.

[SangoProduction]

It probably does, I just don't have it in my notes, and don't have the book on me.