You may give Henneth Annûn Guard doomed 1 when you play it from your hand. If you do, it gains:

Response: After you play Henneth Annûn Guard, choose a character. Until the end of the round, that character gets +2 and gains sentinel.

"Does he think that men sleep without watch all night?" –Faramir, The Two Towers

Response: After Galadriel’s Handmaiden enters play, choose a player. That player reduces his threat by 1.

Her maidens stood silent about her, and a while she looked upon her guests. –The Fellowship of the Ring

Cannot have restricted attachments.

Enters play exhausted.

There were songs about the hunt of the Ents for the Entwives sung among Elves and Men from Mirkwood to Gondor. –The Two Towers

Sentinel.

They now learned to their joy that Erkenbrand had left many men to hold Helm's Gate, and more had since escaped thither. –The Two Towers

Cannot have restricted attachments. Enters play exhausted.

Booming Ent gets +1 for each damaged Ent character you control.

"...a man that hacks once at an Ent never gets a chance of a second blow." –Merry, The Two Towers

Response: After Weather Hills Watchman enters play, search the top 5 cards of your deck for a Signal card and add it to your hand. Shuffle the other cards back into your deck.

"Rangers use runes, and they come here sometimes." –Aragorn, The Fellowship of the Ring

Forced: After Dúnedain Hunter enters play, search the top 5 cards of the encounter deck for a non-unique enemy and put it into play engaged with you. If no enemy enters play by this effect, discard Dúnedain Hunter. Shuffle the encounter deck.

Response: After Sarn Ford Sentry enters play, draw 1 card for each enemy engaged with you.

"Lonely men are we, Rangers of the wild, hunters but hunters ever of the servants of the Enemy..." –Aragorn, The Fellowship of the Ring

Warden of Annúminas gets +1 for each enemy engaged with you.

Rangers passed at times beyond the hills, but they were few and did not stay. –The Fellowship of the Ring

Encounter. Surge. Ranged. Sentinel.

When Revealed: The first player chooses a player to take control of Ranger of the North. Then, either deal 2 damage to an enemy or place 2 progress tokens on a location.

X is the number of quest cards in play.

The first player gains control of Iârion.

Response: After a side quest is revealed from the encounter deck, ready Iârion.

If Iârion leaves play, the players lose the game.

Response: Exhaust Honour Guard to cancel 1 point of damage just dealt to a character.

Valour Response: Exhaust and discard Honour Guard to cancel up to 5 damage just dealt to a character.

Forced: After the active location is explored, place Curious Brandybuck on the bottom of its owner's deck.

Response: After you travel to a location, put Curious Brandybuck into play from your hand, under any player's control.

East Road Ranger gets +2 while committed to a side quest.

"If you bring a Ranger with you, it is well to pay attention to him..."
–Gandalf, the Fellowship of the Ring

Response: After you engage an enemy, if you control at least 1 Dúnedain hero, spend 1 resource to put Ranger of Cardolan into play from your hand, under your control. At the end of the round, if Ranger of Cardolan is still in play, shuffle it into its owner's deck.

Veteran of Osgiliath gets +1 , +1 , and +1 while your threat is 40 or higher.

"So do we ever watch the shores nigh Osgiliath, which our enemies now partly hold, and issue from it to harry our lands."
–Faramir, The Two Towers

Sentinel.

Cannot have restricted attachments. Enters play exhausted.

While Derndingle Warrior is defending, it gains:

Action: Deal 1 damage to Derndingle Warrior to give it +3 for this attack. (Limit once per attack.)

Discard 2 cards from your hand to put Elven Jeweler into play from your hand, under your control.

"...to the Elven–smiths they were but trifles..." –Gandalf, The Fellowship of the Ring

Action: Discard 2 cards from the top of your deck to give Longbeard Sentry sentinel and +1 until the end of the phase. (Limit once per phase.)

"...many of them have had experience in the dreadful dwarf and goblin wars, of which you have no doubt heard."
–Bilbo Baggins, The Hobbit

Cannot have restricted attachments.

Enters play exhausted.

Response: After Wellinghall Preserver readies, heal 1 damage from an Ent character.

Cannot attack or defend.

Response: After Galadhrim Weaver enters play, shuffle the top card of your discard pile into your deck.

"You are indeed high in the favour of the Lady! For she herself and her maidens wove this..." –Lórien Elf, The Fellowship of the Ring

Sentinel.

Guardian of Arnor gets +1 for each enemy engaged with you.

"Travellers scowl at us, and countrymen give us scornful names."
–Aragorn, The Fellowship of the Ring

Ranged.

Fornost Bowman gets +1 for each enemy engaged with you.

To the last battle at Fornost with the Witch–lord of Angmar they sent some bowmen to the aid of the king...
–The Fellowship of the Ring

Response: After Galadhrim Healer enters play, choose a player. Heal 1 damage from each hero controlled by that player.

"Even if your Quest did not concern us closely, you should have refuge in this City, until you were healed and refreshed."
–Celeborn, The Fellowship of the Ring

While the top card of your discard pile is an ally, Mithlond Sea-watcher gets +2 and gains ranged.

But it was an old tradition that away over there stood the Grey Havens, from which at times elven-ships set sail, never to return.
–The Fellowship of the Ring

While the top card of your discard pile is an attachment, Warden of the Havens gets +2 and gains sentinel.

"...and if he comes, assailing the White Towers and the Havens, hereafter the Elves may have no escape from the lengthening shadows of Middle-earth."
–Galdor, The Fellowship of the Ring

Lindon Navigator does not exhaust to commit to a quest, and can commit to quests while exhausted.

Forced: After resolving a quest to which Lindon Navigator was committed, either discard it from play or discard 1 card from your hand.

While the top card of your discard pile is an event, Sailor of Lune gets +1 and gains: "Cannot be damaged while committed to the quest."

"They are sailing, sailing, sailing over the Sea, they are going into the West and leaving us," said Sam, half chanting the words, shaking his head sadly and solemnly.
–The Fellowship of the Ring

Action: Discard a card from your hand to heal 1 damage on any character. (Limit twice per round).

"You are in Rivendell, and you need not worry about anything for the present."
–Gandalf, The Fellowship of the Ring

As an additional cost to play Guardian of Rivendell from your hand, you must discard 2 cards from your hand.

"Indeed there is a power in Rivendell to withstand the might of Mordor, for a while."
–Gandalf, The Fellowship of the Ring

Response: After you play Master Ironsmith from your hand, if you paid all of its resource cost from a single hero's resource pool, attach a Weapon or Armor attachment from your hand or discard pile to that hero without paying its resource cost.

Response: After Mirkwood Explorer quests successfully, place 1 progress on it.

Action: Exhaust Mirkwood Explorer to move all progress from it to a location in play.

Response: After Rhovanion Outrider commits to the quest, place 1 progress on a location in the staging area. If that location is not explored by this effect, give Rhovanion Outrider +1 until the end of the phase.

Response: After Ered Luin Miner is discarded from your deck, put it into play under your control.

Tools were to be found in plenty that the miners and quarriers and builders of old had used; and at such work the dwarves were still very skilled.
–The Hobbit

Forced: At the end of the round, discard Dwarven Sellsword unless the players as a group spend 1 resource.

...he did not altogether approve of dwarves and their love of gold...
–The Hobbit

Ranged.

Response: After Marksman of Lórien enters play, choose an enemy. That enemy gets -2 until the end of the round.

"Keen are the eyes of the Elves."
–Aragorn, The Two Towers

Response: After Woodland Courier enters play, place 1 progress on a location (2 progress instead if that location has the Forest trait).

Veteran Sword-elf gets +1 and +1 for each copy of Veteran Sword-elf in your discard pile.

The elves were the first to charge. Their hatred for the goblins is cold and bitter.
–The Hobbit

Response: After you play Linhir Sea-captain from your hand, if you paid all of its resource cost from a single hero's resource pool, both that hero and Linhir Sea-captain do not exhaust to quest this round.

Knight of the White Tower's resource cost must be paid from a single hero's resource pool.

"...to be only a man of arms of the Guard of the Tower of Gondor is held worthy in the City, and such men have honour in the land." –Beregond, The Return of the King

Response: After Soldier of Dol Amroth enters play, reduce the cost of the next card you play this phase by 1.

...he and his knights still held themselves like lords in whom the race of Númenor ran true
–The Return of the King

Response: After Guardian of Ithilien enters play, return an enemy engaged with you to the staging area.

From such men the Lord Denethor chose his forayers.to harry the Orcs and other enemies that roamed between the Ephel Dúath and the River.
–The Two Towers

Ranged.

Response: After Greenwood Archer enters play, ready a hero.

They dwelt most often by the edges of the woods, from which they could escape at times to hunt...
–The Hobbit

Sentinel.

Response: When you play Erebor Guard from your hand, discard the top 2 cards of your deck to reduce its cost by 2.

...the fortress of the dwarves could not be taken by surprise. –The Hobbit

While there is a side quest in the victory display, Halfling Bounder gains:"Response: Discard Halfling Bounder to cancel the 'when revealed' effects of an encounter card that was just revealed from the encounter deck."

"The Bounders have never been so busy before."
–Sam Gamgee, The Fellowship of the Ring

While there is a side quest in the victory display, Vigilant Dúnadan does not exhaust to defend.

"I don't think we've rightly understood till now what they did for us."
–Barliman Butterbur, The Return of the King

Response: After you play Andrath Guardsman from your hand, choose a non-unique enemy engaged with you. That enemy cannot attack you this round.

They forgot or ignored what little they had known of the Guardians, and of the labours of those that made possible the long peace of the Shire.
–The Fellowship of the Ring

Action: Exhaust Kahliel's Tribesman to choose another Harad character. That character gets +1 +1 and +1 until the end of the phase.

But the Haradrim, being now driven to the brink, turned at bay, and they were fierce in despair...
–The Return of the King

Forced: After this ally enters play, search the top 5 cards of the encounter deck for a non-unique location and add it to the staging area. If no location enters play by this effect, discard Dúnedain Pathfinder. Shuffle the encounter deck.

Response: When the active location leaves play as an explored location, discard Eryn Galen Settler to discard a location in the staging with the same title as the just explored location.