Whether it's a good old-fashioned expansion pack or modern DLC, spinning additional content for already-released games has been a standard practice in the industry for decades. But the best expansions do more than simply add a few extra hours of the same game for you to play.
They enhance the ideas and systems explored in their parent games, condensing them down into a smaller, tighter package that function as self-contained entities — some go even further, enriching the player's experience of the original game itself by providing further insight into the game's world, filling voids in the game's story, or introducing new mechanics that offer fresh ways of play.
With this in mind, we've put together a list of our 10 favourite game expansions, works that happily stand as brilliant creations in their own right, but also augment the ideas and themes of the game that came before them.
Dishonored: The Brigmore Witches
Dishonored's first expansion pack, The Knife of Dunwall, addressed many of the original game's problems. Its switch of protagonist from the vengeful Corvo Attano to the amoral Assassin Daud proved a more sensible fit for the game's adaptable play-styles, while the missions expanded upon some of the less explored areas of the world's lore. But it also felt distinctly incomplete, almost like foundational work upon which to build something greater.
This turned out to be The Brigmore Witches, the culmination of Arkane's work on Dishonored. It enriches the experience as a whole, tying together Daud and Corvo's stories, and providing greater insight into the weirdest elements of Dishonored's world.
Moreover, its three missions infiltrating Coleridge Prison, exploring the factional conflicts in Draper's Ward, and surviving the dilapidated Brigmore mansion - are the pinnacle of Dishonored's level and environment design, and this is a game crammed with fantastic examples of both.
Call of Duty: United Offensive
It's surprising that United Offensive doesn't get mentioned more often during discussions of the best expansions. This explosive expansion takes the intense action of the first Call of Duty, and somehow concentrates its essence into something even more ferocious. Within minutes of the game's commencement, you're racing through the snowy forests of Bastogne on a jeep, trees exploding around you as you're chased down by a German tank. And the fighting only gets fiercer from there.
These brutal early missions set during the Battle of the Bulge are undoubtedly United Offensive's highlight, but it also includes a fascinating mission that involves manning multiple gun-batteries inside a B-17 bomber, alongside an homage mission to the Guns of Naverone, and a portrayal of the Russian battle of Kursk, the largest tank battle in history. Indeed, much of United Offensive is stronger than the main game, and yet it is probably the least discussed entry in this long-running series.
XCOM: Enemy Within
Enemy Within is a very different expansion to the others in this list. Rather than delivering multiple hours of extra game in a single chunk, instead it spreads itself throughout the body of Firaxis' Enemy Unknown, altering its DNA in subtle yet fundamental ways.
The most significant of these is the introduction of Meld, an alien substance comprised of nanomachines that lets players upgrade their XCOM operatives with superhuman powers. On missions, Meld canisters self-destruct after several turns, meaning you need to move fast to acquire them. This of course has to be balanced with tactically outmanoeuvring a technologically superior alien force, resulting in some agonisingly tricky strategic decisions.
Enemy Within also introduces power mech units on both sides, an extra enemy faction in the form of alien sympathisers EXALT, and reintroducing the much-desired Base Assault mission which wasn't included in the original release. Enemy Within is all about raising the stakes of Enemy Unknown, and it succeeds brilliantly.
Mass Effect 2: Lair of the Shadow Broker
BioWare are probably worthy of several entries on this list. But I forced myself to choose just one. Mass Effect 3's Citadel came close, but Lair of the Shadow Broker is simply more crucial to the story as a whole.
Indeed, as story-based expansions go, Lair of the Shadow Broker is one of the most important added to any game. Shepard reunites with Liara T'Soni as she attempts to track down and kill the mysterious information dealer known as the Shadow Broker. In the process we witness a significant evolution of Liara's character, which plays into the story of Mass Effect 3.
But Shadow Broker's merits aren't simply down to its narrative consequences. It's also a fabulous little adventure in its own right, including a thrilling sky-car chase and a couple of impressively thought-out boss fights. It also concludes with a superb sequence set on the hull of a space cruiser speeding through a fearsome lightning storm. Lair of the Shadow Broker is a microcosm of BioWare at their very best.
The Chronicles of Riddick: Assault on Dark Athena
There's some debate over whether Assault on Dark Athena constitutes an expansion or a full-on sequel, but the fact that it is considerably shorter than escape from Butcher Bay, and comes packaged with a visually upgraded version of that game, hints at the former. This works nicely for us, because it's bloody good.
Dark Athena shifts the action from Butcher Bay's sci-fi prison to a mercenary spaceship, where Riddick is hunted by an army of remote-controlled cyborgs under the command of Captain Gale Revas. Dark Athena refines many of Butcher Bay's interesting but wobbly systems, particularly the stealth. Riddick can now sneak through shadows effectively, and dispatch enemies quickly and cleanly with his signature Ulak weapons.
The game also boasts a surprisingly strong story which sees Riddick protecting a young girl from Revas and her cronies. The last hour or so is a disappointment, switching out the engaging stealth for some rote and frustrating shooting, but it's a minor blemish on an otherwise excellent expansion.
Red Dead Redemption: Undead Nightmare
One of the most original ideas for an expansion (despite the fact that it involves zombies). Undead Nightmare takes the beautiful Western landscape seen in Red Dead Redemption and switches out its cowboys and bandits for a host of shambling corpses.
The best thing about Undead Nightmare is how it enabled Rockstar to dispense with any pretense of grandeur and simply run wild with their wicked sense of humour. The original game's wildlife, wolves and bears and such, are all replaced with undead equivalents, and wander the games world alongside mythical creatures like Chupacabras and Sasquatches. John Marston can even track down and tame the four horses of the apocalypse, using them as steeds to traverse the game world.
It's the first time in years that Rockstar have wholeheartedly embraced the inherently madcap nature of open world games, and as a result Undead Nightmare is one of their most entertaining creations.
Sonic & Knuckles
No self-respecting discussion of expansion packs would be complete without mentioning Sonic and Knuckles, one of the earliest and most interesting examples of the form. Sonic and Knuckles was famously never intended to be an expansion pack. It was meant to be part of Sonic 3, but time and cost constraints meant the game was split into two parts.
SEGA rescued the situation through Sonic and Knuckles' ingenious "Lock-on" technology, which enables players to insert Sonic 2 and Sonic 3 into the Sonic and Knuckles cartridge, making Knuckles playable in Sonic 2 and transforming Sonic 3 into the game it was originally intended to be. It epitomises the qualities of the best expansions, not only bringing something new, but adding something significant to its parent game as well.
The Elder Scrolls IV: Shivering Isles
Oblivion is often viewed as the weakest of the Elder Scrolls games, although it certainly has its share of interesting quests and locations (Hackdirt anyone?). A complaint that has endured since the moment of its launch, however, was that it lacked the weirdness of Bethesda's previous entry, the brilliant Morrowind.
Shivering Isles was Bethesda's defiant response to this, an expansion that's entire premise revolved around being weird. The Isles are divided into two clear provinces, Mania and Dementia, the former wildly colourful and crammed with strange flora, the latter a dark and swampy wasteland. It's ruled over by the mad God Sheogorath, who is obsessed with cheese and seems to view the removal of someone's entrails as a kind of compliment.
Shivering Isles doesn't make any significant alterations to how Oblivion plays, and there are times when it feels like it's trying a little too hard. But its environmental design remains delightful, and it acts as a wonderfully zany counterpart to Oblivion's staunchly traditional fantasy hodgepodge.
Bioshock 2: Minerva's Den
Minerva's Den is a splendid example of expansion design. It takes the grandiose philosophising of Bioshock and its sequel and condenses them down into something much more personal and relatable. It tells the story of Charles Porter and Reed Wahl, two brilliant scientists who developed the Thinker, the AI machine that controls all of Rapture's automation and security measures. Wahl ultimately betrays Porter and steals the Thinker for himself.
Minera's Den sees you play an Alpha Big Daddy named Sigma, who is activated by Porter to take the Thinker's machine code back, so Porter can rebuild it and use it for its original, philanthropic purpose.
It's a superb distillation of Bioshock's best moments, tackling big ideas like the nature of free will and what it means to be human, but also finding time to reflect on more personal matters like grief and loss. It even has a twist at the end that rivals that of the original Bioshock.
Half Life: Opposing Force
Opposing Force is a sequel in all but name. It ingeniously offers an alternative perspective on Gordon Freeman's escape from the alien-infested Black Mesa facility, casting you as US Marine Adrian Shepard, part of a strike team sent to the facility to contain the situation.
It gleefully plays with the plot established in Half Life, intersecting with Freeman's story at key moments, and adding neat twists of its own. The Marines are initially sent to exterminate any Black Mesa personnel who survived the disaster. Yet as the government's desperation to contain the situation reaches fever pitch, the Marines themselves are hunted down by Black Operations. Shepard also encounters an entirely new species of alien known as "Race X", who further muddy the waters by fighting both the humans and the Xen aliens.
As a straightforward expansion it enhances everything that was great about Half Life; offering more fantastic scripted setpieces and further exploring the Black Mesa facility's powerful sense of place. But it also broadens our understanding of the original game, showing us the motivations behind the Marines' actions and revealing the conspiracy goes far deeper than what was seen in the original Half Life.
This post originally appeared on Kotaku UK, bringing you original reporting, game culture and humour with a U from the British isles.