Treebeard exert

[hsiale]

The cost-effect rule states you pay a cost, then perform as much of the effect as possible.

Yes, but the cost-effect rule has one single exception, which is also mentioned in the rules (in the "effect" section). And this exception is when the effect (or one of the effects) is playing a card in any way except directly from draw deck. Galadriel plays elf from hand, They Are Coming plays orc from discard pile, so both fall under this exception and can't be used according to cost-effect rule.

[TheJord]

I think ES is confused. This rule is to prevent you using They Are Coming in the manner it explains in the rulebook; you cannot use They Are Coming to discard a minion, then play that minion using the effect of They Are Coming.

Galadriel, Lady of Light cannot exert to play an Elf for free, if, by exerting, you will now have an Elf in your hand. Due to the requirement laid out in the rules, effects playing cards from hand or discard pile require you to play that card if you can.

This is the cost-effect rule.

One misinterpreted section of the rulebook does not change this. You have misread this section

If an action plays a card from your hand (or discard pile) as part of its effect, then that card
must be in your hand (or discard pile) before you can begin to perform that action

to mean that the card must be in your hand in order to pay the cost. This is incorrect.

It means, the card would have to be in your hand before the costs are paid in order to be played.

The cost-effect rule is not changed by this one line. You have misread it.

[Elessar's Socks]

This is from the 9/3/2002 CRD, which goes into some more detail:

If you meet all the requirements and pay all the costs for playing a card, you may play that card, even if the card will have no effect.

Exception: If you perform an action that has playing a card from your hand or discard pile as part of its effect, you must play that card.

This exception applies to all kinds of actions (playing event cards, using special abilities, "when you play" game text, and so on) and all the different ways you can play a card (except playing a card from your draw deck).

Examples: You must verify that you have a Moria Orc in your discard pile and enough twilight tokens to pay for that Orc before you discard cards for the action on They Are Coming (remember, you can always look through your own discard pile). You may not use the action on Beneath the Mountains if you don't have a Dwarven weapon in your discard pile. You may not play Morgul Gates if you don't have a Nazgûl in your hand.

So regarding "Can I exert [Galadriel LoL] to use her ability, even if I have no Elf in hand?" I think the answer is still no, but the reason should've been "If you perform an action that has playing a card from your hand or discard pile as part of its effect, you must play that card." I think TheJord is correct in my misuse of the other rule, as that seems to be emphasizing a particular card (i.e. "If you want to play this specific Elf, then that Elf must already be...").

[Tbiesty]

Examples: You must verify that you have a Moria Orc in your discard pile and enough twilight tokens to pay for that Orc before you discard cards for the action on They Are Coming (remember, you can always look through your own discard pile). You may not use the action on Beneath the Mountains if you don't have a Dwarven weapon in your discard pile. You may not play Morgul Gates if you don't have a Nazgûl in your hand.

Interesting.  I wasn't aware of those specific examples.

If that is indeed how it works, then the exception itself was not worded very well to explain that.

It should have been worded more like this:

"Exception: In order to perform an action that has playing a card (except from your draw deck) as part of its effect, you must verify that the card can actually be played before you can perform the action."

[TheJord]

I would still disagree on the Galadriel, Lady of Light example; ie she could exert for no effect, but frankly anyone who did this would deserve to have all their cards burned.

[Elessar's Socks]

If that is indeed how it works, then the exception itself was not worded very well to explain that.

I agree it could have been worded better. Personally the connection made in the CRD seems a bit of a stretch to me, but as I remember something in there stops us from using TAC when nothing can be fetched from the discard pile. I also seem to recall Decipher not liking cycling being too easy, which might be one reason why Don't Look at Them and They Stole It were clarified to having to spot Smeagol/Gollum (as wounding doesn't fall under the exception).

[azogsbane]

The Jord is the high king of rules, so I guess that settles it.

[Not a Zombie]

I would still disagree on the Galadriel, Lady of Light example; ie she could exert for no effect, but frankly anyone who did this would deserve to have all their cards burned.

There is a good reason for doing it, cycling. You have another LoL in your hand. I would say you can't exert and not play an elf, for the same reasons as ES. But I don't care a whole lot either way.

[TheJord]

I would still disagree on the Galadriel, Lady of Light example; ie she could exert for no effect, but frankly anyone who did this would deserve to have all their cards burned.

There is a good reason for doing it, cycling. You have another LoL in your hand. I would say you can't exert and not play an elf, for the same reasons as ES. But I don't care a whole lot either way.

Cycling? How does exerting Galadriel, LoL for no effect cycle?

[Air Power]

It only works if you have another copy in your hand:

exert LoL for no effect (can't play additional copy due to uniqueness)

discard from hand to heal the copy in play

[azogsbane]

It only works if you have another copy in your hand:

exert LoL for no effect (can't play additional copy due to uniqueness)

discard from hand to heal the copy in play

Can you do that with allies? I've always thought that rule only applied to unique companions. But I'd love to be corrected here.

[MarcinS]

Can you do that with allies? I've always thought that rule only applied to unique companions. But I'd love to be corrected here.

Here you go, from "Comprehensive Rules":
""Discard to heal." Spot a unique companion or unique ally with at least one wound and discard a card from your hand with the same card title (it may have a different subtitle) to heal that character."