There are 47 Trophies that can be collected.

Bronze

Where there's life, there's hope    
Revive a fallen ally.     

Foe-hammer    
Kill 200 enemies in a single playthrough.     

Sudden Fury    
Perform 3 critical hits within 10 seconds.     

Strength of Our Alliance    
Slay one enemy together with 2 other players.     

Seeker    
Discover 25 secrets in a single playthrough.     

Gem-studded    
Slot an elfstone into an item.     

Relentless    
While in Hero Mode, perform a streak of 50 hits.     

Now for wrath, now for ruin!    
Kill 4 enemies simultaneously.     

Troll's Bane    
Slay the wild snow trolls.     

Battle-master    
Unlock every active-cast ability in one character’s skill tree.     

War-hardened    
Achieve at least 1 rank in a tier 3 skill tree.

Many deeds, great and small    
Complete 15 quests in a single playthrough.     

War-machinist    
Kill 150 enemies with war machines in a single playthrough.     

Well-arrayed    
Equip all parts of an armor set.     

Keen-eyed Marksman    
Kill 50 enemies with headshots in a single playthrough.     

Swift-winged Warrior    
Summon Beleram 10 times in a single playthrough.     

Warrior Exemplar    
For one character unlock every skill that provides a modification to War Cry, Sanctuary or Evasion.     

Defender of the North    
Achieve level 10.

Herb-master    
Create 15 potions in a single playthrough.

Dragon-hoard    
Amass 25,000 coins.

Silver

Like a Thunderbolt    
Deal 3000 damage with a single ranged strike.     

Fell-handed    
Deal 1500 damage in a single melee strike.     

Living Shield    
Absorb 25,000 total damage during the course of 1 level.

Champion of the North    
Achieve level 20.

Bane of Mordor    
Kill 600 enemies in a single playthrough.

Expert Treasure-hunter.    
Locate 5 gilded treasure chests in a single playthrough.     

Victorious in Battle    
Complete a playthrough on at least Normal difficulty.     

Against All Odds    
Complete a playthrough on Legendary difficulty.     

The Lidless Eye    
Complete the investigation of the Cult of the Lidless Eye.     

Hero of Legend    
Complete a playthrough on Heroic difficulty.

Platinum

Warrior of the North    
Earn all trophies for Lord of the Rings: War in the North

16 Secret

http://www.ps3trophies.org/game/lord-of-the-rings-war-in-the-north/trophies/