The Lord of the Rings Online: Riders of Rohan
The Lord of the Rings Online: Riders of Rohan is the fourth expansion for the Massively multiplayer online role-playing game The Lord of the Rings Online. It was released on October 15, 2012 as a web-based download and on Steam. New game enhancements include a level cap increase to 85, level 85 legendary weapons (as well as a new legendary item), and six new areas.  The expansion's main feature is mounted combat.

Storyline

Volume III: Allies of the King
Riders of Rohan continues the storyline that began shortly after The Lord of the Rings Online: Siege of Mirkwood expansion and is described in The Lord of the Rings Online: Rise of Isengard.

Book 7 - A Fellowship Endangered

Her wounds healed, the Dunlending girl Nona makes a full recovery and becomes eager to leave Lothlorien. Lady Galadriel's mirror reveals to her and the player that the Fellowship faced a grave danger at Parth Galen, but many things remain unclear. Galadriel bids the player and Nona to travel further down the river of Anduin to discover the Fellowship's fate, sending with them guide - an Elf named Corudan, whose sister Sigileth fought alongside the player in Mirkwood and perished during the battle in Dol Guldur. The Fellowship makes a brief stop at the Rohirrim town of Stangard, where the player discovers that Horn, the man who helped carry wounded Nona into Lothlorien, is no longer welcome by other men for venturing into the woods they consider haunted. His future uncertain, Horn accepts the offer to join the player's quest. Together with an Elf, a man of Rohan and a girl from Dunland, the player travels by boat south down Anduin, eventually reaching the Argonath. On the lawn of Parth Galen, they find signs of the Fellowship's passing and a struggle and are eventually able to piece together the events leading to the Breaking of the Fellowship. This goal accomplished, they decide to pursue the Three Hunters and aid them in rescuing Merry and Pippin from the Uruks who captured them.

Book 8 - Into the Riddermark

Already days behind Aragorn, Legolas and Gimli, the Company has no hope of catching up with them on foot. They set to acquire War-Steeds from the friendly Rohirrim in the town of Langhold. While the Three Hunters led their pursuit on foot without stopping for rest, the player's company now has the benefit of the mounts, but makes several stops at Rohirrim towns along the way, to get a better direction of where the passing Uruks went. After departing the town of Faldham, where Elfhelm's son Elfmar rules in his father's absence at the Fords of Isen, they make their way to Eaworth in the Entwash Vale, near the edge of Fangorn Forest. Horn's father Ingbert is the Reeve - ruler - of this town and the vale itself, but is not pleased to see his son, for Horn had a term to serve in the town of Stangard, which he now broke. Adding more tension is the fact that Horn and Nona, despite all their differences, have begun to show signs of affection for each other during the long journey, but few in Eaworth are even being able to tolerate to presence of a "wild Dunlending" among them. Offended by such welcome, Nona leaves silently and without saying goodbye. Unable to find her trail, the player, Corudan and Horn have no choice but to continue with their original mission.

Book 9 - The Third Marshall

Éomer and his riders make a stop at Eaworth while returning to Edoras. The Third Marshall says to the player the same thing he earlier said to Aragorn: that his riders have killed the Uruks and burned their bodies, with none left alive. The player and his/her two companions set out to investigate the site of the battle nonetheless. Lacking Aragorn's superior tracking skills, they miss the signs of the Hobbits having escaped and nearly succumb to despair. However, a chance encounter with an Ent from Fangorn reveals that not only are the Hobbits alive, but that Gandalf himself has already seen for their safety. Their hopes renewed, the player, Horn and Corudan the Elf decide to travel with Eomer's eored for a time.

Eomer's next stop takes him to the town of Snowbourn on the river of the same name. The Third Marshall deems the entire Eastemnet not defensible, with Isengard forces coming from the west, Mordor orcs pouring from the south and Easterlings crossing the river from the east. By his military power, he orders all people remaining in those lands to abandon their homes and move westward across the Entwash river, where they can be better defended. Fastred, the Thane ("Major") of Snowbourn openly defies this order, however, refusing to abandon his position and leading bold strikes against orc forces instead. Angered at the insubordination, Eomer decides to bring this matter directly to the attention of the King.

The player and his companions accompany Eomer to Edoras, where the sings of Grima Wormtongue's growing influence become apparent to all after The King's Minstel Gléowine is thrown out of the court for crossing him. The audience with King Theoden quickly turns into an interrogation by Wormtongue, who orders Eomer stripped of his rank and imprisoned for breaking the "King's" direct order not to pursue the Uruk-hai band. Only an intervention by Lady Eowyn saves the player, Corudan and Horn from similar fate - instead they are thrown out of Edoras and are ordered to remain in the Eastemnet, not to cross the Entwash river under the penalty of death. Their next move uncertain, the trio decides to spend time helping those people who choose to fight for their homes in this land, despite being abandoned by Edoras.

Book 10 - Snows of Wildermore

The player, Horn and Corudan choose to follow Gléowine, King Théoden's minstrel and Horn's old mentor, who has been thrown out of Edoras along with them. They find him in Snowbourn, where they hear troubling news from Harding, Aldor of the Northmarch - no word has come from Wildermore, in remote corner of the Wold, for weeks. Wildermore is where Gléowine spend his youth and a chance to revisit those lands gives him a new purpose. He joins the player's companions as they travel to the Wold and then to Wildermore. The find the land engulfed in snow, highly unnatural for those lands, and terrorized by a stone giant named Nurzum. A foul product of Saruman experiments, he had his strength augmented with remains of an ancient Huorn, making him nigh invulnerable, and a relic of Morgoth from Thangorodrim fused to his back, causing unnatural cold, snow storms and ice to follow him whenever he goes. Widfara, one of Harding's men from the Wold, is a sole survivor of his attack, and believes everyone else, including Harding's son Leodwig, killed.

While traversing Wildermore in search of ways to oppose Nurzum, the player and his companions unexpectedly come across Nona. Since her departure in Eaworth, she made her way to the city of Byre Tor, which has been razed by Nurzum, and cared for the survivors, her hatred for Men of Rohan lessened by the kind actions. Her reunion with Horn is brief and cold, and not having yet resolved her feelings for him, she chooses to leave again. The others follow her to a cave where she hides survivors from the snow, among them Harding's son Leodwig, injured but alive. Seeing wrath of Nurzum firsthand, Corudan the Elf decides to search for aid among the Ents of the nearby Fangorn Forest. He and the player manage to find and wake the Ent Leaflock (Finglas) and relay him Nuzum's story. The Ent cares little for troubles of Men, but defiling of Huorn's remains rouses him to anger and he commands Huorns of the forest to come after the giant. Nurzum fights off the attack, but is weakened and later defeated by the player and Heroes of Wildermore. Meanwhile, Nona and Horn resolve their feelings and finally commit to each other.

Interludes

A series of session plays running concurrent to Book 10 shows the Rangers of the Grey Company whom the player left in Book 5 and their activities in Dunland, without the player character's involvement.

Meanwhile, the Grey Company of Dunedain remains in Dunland, where following their rescue from imprisonment in Tur Morva, the Rangers drove the traitorous Falcon Clan underground. The Ranges occupy the city itself and fight off several smaller ambushes, but don't have the force to assault the Dunlendings in the tunnels under Methedras, for the Falcon Clan knows them much better, resulting in a stalemate. The Sons of Elrond bid Halbarad to continue the journey south, yet many Rangers refuse to leave without having vengeance for their fallen brothers. The Ranger Saeradan, with Halbarad's permission, leaves the company and takes a wagon with the bodies of the fallen north, to prevent their defilement in the hostile lands. Upon reaching Enedwaith he makes an important discovery - the Oathbreakers of the Forsaken Road, responsible for an earlier attack on the Rangers, have left those lands and are travelling back to the Stone of Erech, hoping to be relieved of their eternal curse. In Tur Morva the Ranger Golodir refuses to wait for vengeance any longer and enters the caverns accompanied only by his friend Corunir. There they discover that the Falcon Clan has tricked them again and used the underground passages to cross the Misty Mountains into the lands of Rohan. In Isengard, the Ranger Lothrandir is still holding out against physical and mental abuse by Saruman's servants, but the Wizard has patience and is determined to break him.

New zones
The Riders of Rohan expansion features six new regions, all part of the Eastemnet: The Wold, The East Wall, The Norcrofts, The Sutcrofts, The Entwash Vale, and The Eaves of Fangorn.  Players begin their adventures in Rohan by traveling south of the Great River area to The Wold.  As they continue their journey, they make their way through all the regions in the Eastemnet, ultimately reaching the level-85 area of The Sutcrofts.

Mounted Combat
A major, new gameplay feature that is being added is Mounted Combat.  Early in their adventures, players will have the opportunity to acquire a War-steed.  This mount is unique in that it allows players to engage in combat while on their horses.  To that end, the war-steeds have been given their own morale and power, and have their own skills.  Players will also acquire new class-specific skills exclusive to mounted combat, as normal "on-foot" skills are not usable.  Riders of Rohan also features mounted enemies, and players are encouraged to take advantage of the benefits of being on a war-steed when fighting these enemies.

War-steed movement
Movement on war-steeds is not like movement on the travel mounts that have previously been featured in The Lord of the Rings Online.  War-steeds accelerate slower, decelerate slower, and have a much wider turning radius than the smaller, northern horse breeds.  In this manner, war-steeds behave more realistically than travel mounts.  As a war-steed accelerates to its top speed (which is significantly faster than the northern horses), it accumulates a new feature called Fury.  Fury amplifies the damage done to enemies as well as the healing done to allies.  Because of this new feature, mounted combat is intended to be primarily similar to jousting, in which players ride a distance, gaining speed and Fury, and unleash a single, massive hit on the enemy.  The player then rides off, gathers more speed and Fury, turns about, and rides at the enemy again until victory (or defeat).

Types of war-steeds
Initially, players will acquire the "War-steed: Medium" mount, known as a Rouncey.  This mount has a good balance of survivability, maneuverability, and damage potential.  Players who have purchased the expansion are free to choose 2 alternatives, the War-steed: Light and the War-steed: Heavy.  Players who have not purchased the expansion can purchase these alternatives with Turbine Points.  The War-steed: Light (the Courser) is more maneuverable than its Medium and Heavy counterparts, but sacrifices survivability in exchange.  The damage potential for Coursers and Rounceys are about the same.  The War-steed: Heavy (the Destrier) sacrifices some damage potential and some maneuverability for survivability.

War-steed traits
In addition to the 3 different types, each type has 3 different trait-trees: Red Dawn, Riddermark, and Rohirrim. As the war-steed levels up (to a maximum of 50), points are awarded to the player, who can spend points in each trait-tree. As players spends points in one of the 3 trees, they will unlock passive bonuses and sometimes, more mounted combat skills. In addition, more potent traits are unlocked as players spends points in a given tree.  Each tree is different for every class, resulting in innumerable customizations/configurations for players to choose from. For example, the Red Dawn trait-tree for a Rune-keeper (light-armored caster class) is different from the Red Dawn trait tree of a Guardian (heavy-armored tanking class).  Despite the class differences, Red Dawn focuses more on offense; Riddermark focuses on a balance of offense, maneuverability, and survival; and the Rohirrim trait-tree focuses on maneuverability and survival.

Stances and skills
As traits-trees are filled out, Mount Skills become available. These skills directly affect how war-steeds behave (e.g., one skill causes a war-steed to automatically follow an enemy). In this manner, Mount Skills can be thought of as skills that the war-steeds themselves possess (although they are still found in the character Skills Panel). In addition to Mount Skills, each class will be granted separate Mounted Class Skills.  The first 3 skills granted are stances that reflect what role the player is filling:

Discipline: Red Dawn - primarily for offense
Discipline: Riddermark - some offense, with some maneuverability and survivability
Discipline: Rohirrim - mostly defense, with a few maneuverability features
Upon mounting a War-steed for the first time, the default stance is Red Dawn. Choosing a different stance will change the effects of some of the Mounted Class Skills that each class is given to align with the chosen stance. Mount Skills and Mounted Class Skills are only usable under the following conditions:

The player is mounted on a war-steed.
The player is in Rohan.
The player is not in a combat-restricted area, such as inside a town

Innumerable combinations
War-steed types, traits, and skills/stances are independent of each other. It is possible for a Hunter (traditional ranged-damage class) to ride a Courser in Red Dawn stance with all his/her Red Dawn traits slotted. This configuration would make the mounted Hunter very effective at dealing ranged damage to enemies, with good maneuverability and speed. However, it is also possible for the same Hunter to ride a Destrier in Rohirrim stance with all his/her Rohirrim traits slotted. This would make the Hunter very strong, able to survive a relatively high amount of damage.  This would, however, be to the sacrifice of the Hunter's ability to inflict damage as well as of maneuverability. Instead, there are Rohirrim-specific skills at which the Hunter would excel.

It is also possible for a Guardian (traditional tanking class) to ride the heavy Destrier steed, traited for Riddermark, and position him-/herself in Red Dawn stance. The Destrier steed would help the Guardian's survivability, the Red Dawn stance would allow the Guardian to inflict substantial (but not spectacular) damage, and the Riddermark traits would grant the mounted Guardian abilities that may not necessarily amplify either survivability or damage potential, but would bring yet a third component to bear against his/her enemies.  The steed/stance/traits do not have to match (although, in some cases, it is advantageous to do so).

Aside from even that number of combination, each set of combinations will differ by class. So the aforementioned Guardian with a Destrier steed/in Red Dawn stance/traited Riddermark will differ from a hunter with a Destrier steed/in Red Dawn stance/traited Riddermark. As such, there are an incredible number of combinations to be explored.

Warbands
In the Shores of the Great River update to the Rise of Isengard expansion, the concept of nemesis-class enemies roaming the landscape was introduced.  These enemies occupied a specific area in the Great River region, and were expected to be engaged in a group.  Riders of Rohan extends this concept further by grouping these difficult enemies together with several, less-dangerous enemies and allowing these groups to roam all of Rohan. In most circumstances, these warbands are intended to be engaged by groups of players on horseback.  Players can engage these warbands on foot, but suffer a severe disadvantage when doing so. Warbands frequently have mounted enemies as members, and they will frequently employ the same tactics that players will use when mounted. (Despite the name, warbands to do not make use of the Warband Maneuver, which is a means by which Monster Players and NPC enemies can employ Fellowship Maneuvers against players.)

Open-tapping
Traditionally in MMORPG's, the practice of "power-leveling" is discouraged.  Power-leveling is a situation where a low-level character is paired with a high-level character.  The high-level character then quickly mows through the low-level content, allowing the low-level character to reap the benefits with little/no effort.  This practice is usually done to quickly bring a new character to a high-enough level to engage in end-game content.  However, this is discouraged for several reasons:
The player has little opportunity to learn how to effectively play the new character.
Much of the content that is expected to be played is skipped, effectively reducing the return on investment for the production of the low-level content.
Frequently, power-leveled characters are sold to players for real-world money.  This is usually in violation of the Code of Conduct/Terms of Service agreement with the developer of the game.
Lord of the Rings Online employs a mechanism called "tapping," which is a way for the game to detect who attacked an enemy.  The game can then decide, based on who attacked an enemy first, whom to give experience to and how much to give.  If players try to power-level, they will find that the high-level character will absorb most of the experience (frequently going to waste), and the low-level character will receive just a small fraction of the experience for the defeat of the enemy, even if the characters are not in a group.  The main problem with this method is that it discourages players from helping other players if they randomly stumble upon each other.  For example, if one player is fighting an enemy and is losing the fight, and another player stumbles upon the fight and helps the nearly-defeated player, the nearly-defeated player will lose most of the experience from victory over the enemy.  In the past, this has caused tension between players who appreciate the help and players who would rather suffer defeat than the loss of the experience reward.

In addition to the tapping mechanism, players in a group are expected to share the loot reward granted by a defeated enemy.  The first player in a group to loot a corpse generally is awarded its entire contents, and unless specific rules are set up in-game, no one else in the group gets any of the loot reward.  When rules are set up, players can "roll" for a random number between 1 and 100 for each item; highest roll wins the item.  Players can decide the level of value at which items are shared vs. the ones that are automatically given to the first player to loot the corpse.  Even when all loot is designated to be shared via random chance, only one player can win a given loot reward.  If players are not in a group, the first player (or group) to tap an enemy will be awarded the loot reward, and anyone who assists will not receive any reward.

Because Rohan is intended to be a high-level region anyway, and because leveling in Lord of the Rings Online is accomplished primarily by questing rather than defeating enemies, the penalty for "power-leveling" and shared loot has been removed in Rohan.  Instead, every player who taps an enemy (or heals another player who has tapped an enemy) will get full experience and loot rewards when the enemy is defeated, even if other players help in defeating the enemy.  Players are free to engage an enemy without the risk of "stealing" someone else's experience reward or, conversely, having their experience "stolen."  If a player finds him-/herself on the losing end of a fight with a warband, anyone else who witnesses the impending defeat can step in and assist with no penalty to either the assistee or the assistor.  This practice encourages players to help each other, whether they are grouped or not. The new tapping rules were initially only implemented in Rohan, but due to positive player feedback were expanded to the rest of the game world in an update later that year.

Remote looting
Traditionally, after defeating an enemy, players must move to the corpse to retrieve any loot reward from it.  Because combat in Rohan is intended to be on horseback, and because it is incredibly inconvenient to swing the war-steed around just to loot a corpse, Riders of Rohan introduced the concept of Remote Looting.  Instead of having to travel back to a defeated enemy's corpse, loot rewards are automatically placed into the Remote Loot panel.  An alert is then displayed to the player which, when clicked, will open the Remote Loot panel.  This panel will hold a maximum of 50 items for 1 hour (in game time, not real time).  If any subsequent items are added before 1 hour has expired, the oldest items will be purged first.  If the player waits more than an hour, items that have been in Remote Loot for that hour will be purged.  Each item has its own timer.  Once the Remote Loot panel is opened, the player can opt to retrieve the loot or discard it.  Loot rewards discarded from the Remote Loot panel are irretrievable.  Players are not able to place items from their inventory back into Remote Loot.  Stacks of items will be placed into Remote Loot, but subsequent items of the same type will not stack with each other; they count as separate items.  For example, if a player is awarded 3 Athelas Potions, the whole stack of 3 will be placed into Remote Loot as 1 item.  If the player is later awarded 2 more Athelas Potions, the new stack of 2 will not stack onto the existing stack of 3.  The stack of 2 will occupy a separate item slot in Remote Loot, until the player retrieves the items.  The new looting rules were initially only implemented in Rohan, but due to positive player feedback were expanded to the rest of the game world in an update later that year.

OS X client
Prior to Riders of Rohan, there was only a native game client for Microsoft Windows.  Players who wished to play LOTRO on an Apple Macintosh had to use either Windows-emulation software, or use Apple's Bootcamp to install Windows on their computer.  During the Riders of Rohan beta testing phase, Turbine released a native OS X client for testing.  This OS X client was not released as part of the expansion, presumably due to its not quite being ready for production.  The OS X client was released on November 1, 2012.

Soundtrack
Critically acclaimed video-game composer Chance Thomas contributed several tracks to the Riders of Rohan expansion.  Turbine has released the Riders of Rohan soundtrack for purchase separately.  In addition, the soundtracks from previous Lord of the Rings Online releases Shadows of Angmar and Mines of Moria (to which Thomas also contributed tracks) were made available for separate purchase.

Critical reception

Riders of Rohan won the 2012 Best Expansion of E3 Award by Ten Ton Hammer. IGN gave the expansion an 8.3/10.