Happy to find use in a spell which I have never seen used in play.

[Magesmiley]

Reduce.

This spell is primarily useful for removing reach from large opponents. The Side effect to this you give that opponent +2 AC and -1 to dmg. It's a little bit of a wash.

This isn't as valuable as you might think - you have to remember that it only affects humanoids . Its useless against ogres and the like.

 

[Stalker0]

Its great for rogues with weapon finesse. It gives them a +2 to their attacks, +2 to their AC...and who cares about a -1 to damage when I'm doing +3d6 SA?

 

[shilsen]

Yes, but you become immune to grapple from Large and Larger critters. Not bad.

Do you have a source for that rule? It seems vaguely familiar, but I'm darned if I can find it.

 

[The Grackle]

I'm playing in a module now w/lots of kobolds and tiny passage ways and traps triggered by weight. It's the one time reduce person would totally rock, and we don't have an arcane caster.

 

[Jack Simth]

Do you have a source for that rule? It seems vaguely familiar, but I'm darned if I can find it.

I think he's got it backwards.....

Step 3: Hold. Make an opposed grapple check as a free action. If you succeed, you and your target are now grappling, and you deal damage to the target as if with an unarmed strike.

If you lose, you fail to start the grapple. You automatically lose an attempt to hold if the target is two or more size categories larger than you are.

In case of a tie, the combatant with the higher grapple check modifier wins. If this is a tie, roll again to break the tie.

(Emphasis added)

So Enlarge Person makes a medium humanoid immune to grapples from Small critters ... who don't usually grapple anyways.

 

[Infiniti2000]

You do know that the spell is reduce person, not reduce planks, right?

The OP clearly said "reduce" and not "reduce person". Obviously then the OP is using 3.0 rules. The target line for reduce is "Target: One creature or object of up to 10 cu. ft./caster level". But then you get into the really healthy debate on the definition of an object or a part of an object.