Can a creature choose to do less damage on a attack?

[Lord Phrofet]

So there is a which in our party who is a cartomancer. With the ability to deliver touch spells the card does not do any damage but the player also wants to put conductive (+1 enhancement that allows the delivery of supernatural abilities through the weapon) on the deck as well. The question is two part:

If not using it to deliver a touch spell could a witch still do choose to do no damage?

If a is no, can you choose to do less damage (for example only deal 1 damage from the damage die)?

[Claxon]

Neither of those are covered within the rules.

My answer would be no, and I would tell him to get the merciful enchantment on his deck.

Quote:

Merciful: The weapon deals an extra 1d6 points of damage, and all damage it deals is nonlethal damage. On command, the weapon suppresses this ability until told to resume it (allowing it to deal lethal damage, but without any bonus damage from this ability).

Faint conjuration; CL 5th; Craft Magic Arms and Armor, cure light wounds; Price +1 bonus.

Dealing non-lethal damage is about as good as you can get within the rules. Whenever you receive healing, you heal an equal number of non-lethal damage as well as lethal.

[Rub-Eta]

You can also take a -4 to hit to deal nonleathal with a normal weapon.

[Lord Phrofet]

Yeah that is what I figured.

As a side note I figured a great work around: simply have the witch cast guidance (a 0 lvl spell that gives a +1 on next d20 roll) therefore the card does no damage, still delivers the desired hex to the ally and gives a nice +1 on top of that.

[Lifat]

While there is no written way to reduce damage, it would be a fairly reasonable thing to allow. Like a person "pulling" the punch so to speak.

[Byakko]

As above, there's no inherent way to reduce the damage you deal.

I often see GMs allow you to not apply your Strength modifier, if you desire, however.