Metamagic rods, use when casting or preparing?

[Hiro Quester]

This is my first time playing a prepared caster (druid) in a mostly core game.

My character has just acquired a metamagic rod of extend spell. And I realize I don't know when to use it.

Do I use it when preparing spells, like the feat? Or when casting?

I'm surprised the rules are not clearer about this.

(I'd prefer the former, since I often want to cast spells when in wildshape, when access to and ability to use rods is limited.)

[DeltaEmil]

Metamagic rods confer their ability when the spell is cast.

[Hiro Quester]

Unlike the feat, which you use when preparing spells. Okay. But Is there a rule about this somewhere? I can't find one.

[razorback]

DMG page 236, under Metamagic Rods.

[ericgrau]

It is when casting but it doesn't make much difference. You should use that rod on hour/level spells in the morning anyway. 24 hour buffs are really nice. An extended round/level spell like a summon is pretty meh at level 4 and up. Most combats don't last long enough for it.

If your party has an arcane caster he'll be able to use it better. 24 hours of mage armor is especially nice on a wildshaped druid and his animal companion, unless you can get good barding for it. But if you don't have an arcane caster then there's still goodberry, longstrider and pass without trace. Right before entering a dungeon it's also good for making a min/level spell last for the entire dungeon run. For example shillelagh or mass bear's endurance, among many others.

Whenever possible don't waste a combat round to buff. Combat rounds are too precious. Anything you can do ahead of time is far better. And during a combat other spells are usually better than buffs.

[Hiro Quester]

Thanks, everyone.

Yes, I'm using it in our up-coming dungeon crawl, for 10/min/ level spells, like giving barkskin to the party tank. And shilelaugh on my quarterstaff.

I got the sorcerer a wand of mage armor to save on his spells. I trade him the use of my rod of extend for double duration on his own mage armor,

[Deophaun]

I got the sorcerer a wand of mage armor to save on his spells. I trade him the use of my rod of extend for double duration on his own mage armor,
Wait, does he have mage armor as a spell known? Because that rod won't do anything for a spell cast from a wand (and mage armor cast from a wand lasts only 1 hour).

If he has it as a spell known, you've better off giving him a memento magica (MIC) instead of the wand.

[Hiro Quester]

Wait, does he have mage armor as a spell known? Because that rod won't do anything for a spell cast from a wand (and mage armor cast from a wand lasts only 1 hour).

If he has it as a spell known, you've better off giving him a memento magica (MIC) instead of the wand.

Yes. No MM on the wand, of course.

But we are playing a core game, so no memento magica.

The wand, because we have a wizard and sorcerer, and they are not always both playing. I can lend it to whichever arcane caster can use it to cast on me when I wildshape.