While it is engaged with you, Spiders of Mirkwood gets +1 for each exhausted character you control.

Shadow: Choose and exhaust 1 character you control. If this attack was undefended, also deal that character 2 damage.

Cannot have attachments.

While Goblin Troop is engaged with you, each other Goblin enemy engaged with you gets +1 and +1

Shadow: Attacking enemy gets +2

While Cracked Pillar is in the staging area, it gains: "The first player may declare an attack against Cracked Pillar during the combat phase as if it was an enemy engaged with him. Use Cracked Pillar's as its during this attack."

Travel: Remove 4 damage from Cracked Pillar to travel here.

While Evil Crow is engaged with a player, that player adds 1 to the Hide value for each Hide test he makes.

Shadow: If you have failed a Hide test this round, this attack is considered undefended

While Midgewater is the active location, enemies cannot attack, take damage, or be engaged.

Forced: After Midgewater becomes the active location, return each engaged enemy in play to the staging area.

...there was no permanent trail even for Rangers to find through their shifting quagmires.
–The Fellowship of the Ring

Cannot have non-Morgul attachments.

While Rider of Mordor is engaged with a player, characters that player controls get -1 .

While The One Ring is exhausted, Rider of Mordor gets -10 engagement cost.

While The One Ring is exhausted, Shady Bree-lander gains: "Cannot be optionally engaged."

Shadow: Defending character get -1 (-2 instead if The One Ring is exhausted).

Indestructible.

Cannot be optionally engaged. The Balrog and shadow cards dealt to The Balrog are immune to player card effects.

While in the staging area, The Balrog is considered to be engaged with the first player and only the first player can declare attackers against The Balrog.

While Helm's Gate is the active location, if any player is not engaged with an enemy, the first player reveals an encounter card at the end of each staging step.

Forced: When Helm's Gate is explored, each enemy gets -20 engagement cost and +2 until the end of the round.

While Beleaguered Hills is the active location, reduce the total Threat in the staging area by X, where X is the total Threat of each engaged enemy.

Forced: After Beleaguered Hills becomes the active location, each player engages a non-unique enemy in the staging area.

The onslaught of Mordor broke like a wave on the beleaguered hills...

-The Return of the King

While it is engaged with you, Spiders of Mirkwood gets +1 for each exhausted character you control.

Shadow: Choose and exhaust 1 character you control. If this attack was undefended, also deal that character 2 damage.

Cannot have attachments.

While Goblin Troop is engaged with you, each other Goblin enemy engaged with you gets +1 and +1

Shadow: Attacking enemy gets +2

While Cracked Pillar is in the staging area, it gains: "The first player may declare an attack against Cracked Pillar during the combat phase as if it was an enemy engaged with him. Use Cracked Pillar's as its during this attack."

Travel: Remove 4 damage from Cracked Pillar to travel here.

While Louis is engaged with a player, all Troll enemies gain

"Forced: After this enemy attacks, the defending player must raise his threat by 3."

Response: After defeating Louis, you may choose and discard 1 “Sacked!” card from play.

While Morris is engaged with a player, all Troll enemies get +1

Response: After defeating Morris, you may choose and discard 1 “Sacked!” card from play.

While Stuart is engaged with a player, all Troll enemies get +1

Response: After defeating Stuart, you may choose and discard 1 “Sacked!” card from play.

Regenerate 2. While there is another Tentacle enemy in play, The Watcher cannot be optionally engaged.

If The Watcher is in the staging area at the end of the combat phase, each player must deal 3 damage to 1 character he controls.

Only characters with ranged can attack or defend against Moria Bats.

While Moria Bats is engaged with a player, it gets +1 for each other enemy engaged with that player.

While engaged with a player, Southron Phalanx gets +1 for each location that player controls.

Shadow: Attacking enemy gets +1 for each location the defending player controls.

While engaged with a player, Dunlending Bandit gets +1 for each card in that player's hand.

Shadow: Attacking enemy gets +1 (+2 instead if the defending player has at least 3 cards in his hand).

While engaged with a player, Prowling Wolf gets +1 for each location in the staging area.

Shadow: Defending player exhausts a character he controls.

While Hills of Dunland is in the staging area, it gains:

Forced: After a player draws any number of cards, discard the top card of the encounter deck. If the discarded card is a Dunland enemy, put it into play engaged with that player. This ability does not stack with other copies of Hills of Dunland.

Travel: Each player draws a card to travel here.

While Bellach’s Marauder is engaged with a player, it gains:

Forced: After a time counter is removed from the current quest, deal Bellach’s Marauder 2 shadow cards.

Shadow: Remove 1 time counter from the current quest.

While Ruins of the Second Age is in the staging area, City locations get +1 .

While Ruins of the Second Age is the active location, deal engaged enemies 1 additional shadow card at the beginning of the combat phase.

...as far as Tharbad, where the old North Road crossed the river by a ruined town. –The Fellowship of the Ring

While Borders of Bree-land is in the staging area it gains:

Forced: At the beginning of the quest phase, return 1 enemy engaged with a player to the staging area.

Shadow: Defending character gets -1 for each quest stage in play.

While Southron Sailor is engaged with you, each Ship enemy engaged with you contributes its to the total in the staging area.

”There is a great fleet drawing near to the mouths of Anduin, manned by the corsairs of Umbar in the South.”
–Beregond, The Return of the King

While you are engaged with Umbar Captain, characters you control cannot attack Ship enemies.

...the strength of the rebels in Umbar was a great peril to Gondor...
–The Return of the King

While you are engaged with Soulless Cadaver, your deck cannot be searched.

Forced: When Soulless Cadaver engages you, place each card in your hand with printed cost 2 or less on the bottom of your deck.

Surge.

Eye of the Beast cannot attack.

While Eye of the Beast is engaged with a player, The Thing in the Depths attacks that player during the combat phase (deal and resolve a shadow card for this attack).

While engaged with a player, Faithless Desecrator contributes its to the total in the staging area.

Shadow: Attacking enemy gets +1 (+2 instead if the active location is a Ruins location).

While Drowned Cave is the active location, Undead enemies cannot be engaged (return any engaged enemies to the staging area).

Forced: If Drowned Cave is the active location at the end of the quest phase, each player must discard the top 10 cards of his deck. Then, you may return Drowned Cave to the staging area.

While Southron Captain is in the staging area, each other Harad enemy gets +1

While Southron Captain is engaged with you, each other Harad enemy engaged with you gets +1

Cannot have player card attachments or be optionally engaged.

While the engaged player is engaged with another Orc enemy, Uruk Chieftain cannot take damage.

Forced: At the end of the encounter phase, Uruk Chieftain engages the player engaged with the most non-unique Orc enemies.

Cannot have player card attachments.

While Goblin Troop is engaged with you, each other Goblin enemy engaged with you gets +1 and +1

Shadow: Attacking enemy gets +2

Indestructible. Immune to player card effects.

While Urdug is engaged with a player, he gains,"Forced: At the beginning of the quest phase, Urdug makes an immediate attack. If this attack deals damage, return Urdug and Tiny (if he is in play) to the staging area."

Immune to player card effects. X is 1 more than the number of side quests in the victory display.

Cannot leave the staging are or take more than X damage from non-quest effects each round.

While at least 3 side quests are in the victory display, Dagnir is considered to be engaged with each player.

Indestructible. Immune to player card effects. X is 1 more than the number of quest cards in the victory display.

Cannot take more than X damage each round.

While there are 5 or more quest cards in the victory display, Dagnir cannot leave the staging area and is considered to be engaged with each player.

While there are X or more resources on The Heroes' Defense, Urdug is considered to be engaged with each player, X is five times the number of players.

Response: After an enemy is destroyed, place 1 resource here.

While River Running is in the staging area, enemies cannot be optionally engaged.

Travel: The first player engages the highest engagement cost enemy in the staging area.

...below them were trees that looked like oaks and elms, and wide grass lands, and a river running through it all.
–The Hobbit

While Thane of Ulchor is engaged with a player, Ulchor's Guard engages that player.

Shadow: Attacking enemy gets +2 until the end of the phase.

While Guarded Archway is in the staging area, each player engaged with City Guard cannot reduce his threat.

Travel: City Guard makes an attack against the first player.

X is 2 per player.Indestructible.

Immune to player card effects. Cannot leave the staging area.

While The Challengers is at the same stage as The Wainriders, Wainrider Champion is considered to be engaged with each player.

Venom.

This enemy gets +3 while engaged with a player who controls at least 1 poisoned character.

Shadow: Defending character gets 1 poison. (Give 2 poison to a character you control if undefended.)

While Evil Crow is engaged with a player, that player adds 1 to the Hide value for each Hide test he makes.

Shadow: If you have failed a Hide test this round, this attack is considered undefended

While Midgewater is the active location, enemies cannot attack, take damage, or be engaged.

Forced: After Midgewater becomes the active location, return each engaged enemy in play to the staging area.

...there was no permanent trail even for Rangers to find through their shifting quagmires.
–The Fellowship of the Ring

Cannot have non-Morgul attachments.

While Rider of Mordor is engaged with a player, characters that player controls get -1

While The One Ring is exhausted, Rider of Mordor gets -10 engagement cost.

While The One Ring is exhausted, Shady Bree-lander gains: "Cannot be optionally engaged."

Shadow: Defending character get -1 (-2 instead if The One Ring is exhausted).