After more than a decade in the making, the Warcraft film is finally arriving in theaters. It's based on Blizzard Entertainment's wildly popular Warcraft video game series, a franchise filled with more than two decades' worth of video games, novels and comic books.

It's only natural that the upcoming film adaptation might not adhere 100 percent to the universe's existing lore. After all, this first Warcraft film is largely based off the first Warcraft game, 1994's Warcraft: Orcs and Humans. That first title in the franchise was more concerned with great gameplay and less with telling an emotionally powerful story, so it makes sense that the film version would add new material and tweak some existing lore elements.

The question is how much has been changed? No doubt much of Warcraft's audience will be those who have played World of Warcraft or Blizzard's three Warcraft RTS titles, and these viewers will be more than up to speed on the various intricacies of Azeroth and the First War. That means Warcraft will be walking a tightrope as it tries to please longtime fans of the franchise while still making a film accessible to newcomers.

Judging from the trailers so far, the film looks to be by and large faithful to the source material, even if there are a number of changes that can be spotted. Here's how Duncan Jones' Warcraft looks like it will adapt the beginning of Blizzard's epic high fantasy saga.

Possible Warcraft Movie Spoilers Below!

Orcs

The story of the orcs and their role in the Warcraft universe begins largely with their demonic corruption. Manipulated by the orc warlock Gul'dan, a servant of the demonic Burning Legion, the orcs would slowly be transformed from a proud, shamanistic race into one fueled by rage.

The demonic energy corrupting the orc homeworld of Draenor transforms the orc's skin color from brown to green, though it is worth pointing out that this idea isn't applied with 100 percent consistency. Upon drinking the blood of the demon Mannoroth, the orcs would lose all semblance of their former selves and become consumed by bloodlust.

At the behest of the Burning Legion, Gul'dan and the corrupted human guardian Medivh create a portal to Azeroth, where war quickly breaks out between the invading orcs and caught off-guard humans.

Warcraft looks to follow closely to this basic setup. The orc homeworld is dying because of demonic corruption, the Dark Portal is created and the orcs invade Azeroth to soften up the world for a Burning Legion invasion. Will the orcs in the film drink demon blood? That's currently unclear, but many of the film's orc characters do seem to stay somewhat true to their video game counterparts.

Just as in established lore, it appears that Durotan, leader of the Frostwolf clan, is among the few orcs who choose not to follow Gul'dan's ways.The orc known as Blackhand will become leader of the orcish Horde in the film, much as he does in Blizzard's official history. The half-orc Garona also plays a major role in the events of the film, just as she does in the game.

However, for all the similarities, there are some key differences, chief among them Durotan's role in the war. Due to his refusal to join the Horde, his clan would be exiled. They would seek shelter in Azeroth, only for Durotan and his wife to later be assassinated by orcs loyal to Blackhand and Gul'dan. Because of this, the game version of Durotan never truly takes part in the First War like his film counterpart.

Ogrim Doomhammer also sees a number of changes. He's historically shown to be green in Blizzard's official continuity, but appears brown in the film. It's possible the movie will look to distinguish between brown orcs as good and green orcs as bad, even if that's not exactly how it goes in the game series.

Ogrim's friendship with Durotan also looks to have been greatly expanded upon in the movie, which seems interesting given Ogrim's future. In the games, Ogrim continues to fight for the Horde, though he is wary of Gul'dan and suspects him of treachery. He even becomes leader of the Horde toward the end of the First War in the game version of events, a major plot point that would seem to go against the peace that Durotan and the human champion Lothar are seen trying to achieve in the film's trailers.

The trailers show Ogrim and Durotan to be nearly inseparable in the film, so it should be interesting to see how the relationship shapes future events if a Warcraft sequel ever does arrive.

Humans

All of the game's key human characters - Lothar, Khadgar, King Llane and Medivh - are all represented in Warcraft. Each looks to stay close to their video game counterparts, though Lothar's relationship with Durotan, as seen in the film's trailers, is something unique to the film version of the universe. At no point during the First War is an attempt at peace made between the two warring factions, though Garona does aid Lothar in stopping an increasingly mad Medivh.

What's perhaps more interesting are the new human characters the film looks to have invented. No mention is ever made of King Llane's wife in the game series, though it is presumed he has one. The film, therefore, creates her in the form of Lady Taria. How large her role in the film will be is unclear, but she does have her own poster. But she's not the only new character. Names like Callan, Aloman, Kultiran and Varis all appear on the film's IMDb cast page. It remains to be seen who all these various side characters are, but they will all be creations of the film with no real game counterparts.

The First War

Without having seen the full film, it's tough to say exactly how much will change in Warcraft's depiction of the First War. It's a conflict filled with twists and turns - a failed raid on the human capital of Stormwind, the establishment of various settlements, a search for a lost tome of divinity, yet another raid on Stormwind. No doubt much of the conflict will be streamlined to make for a more sensical movie going experience, one that will bring the characters of Lothar and Durotan into more frequent contact.

We've seen glimpses of important game locations like Blackrock Pass, the Swamp of Sorrows and Stormwind itself in trailers, which seems to imply that Warcraft will follow some of the main beats from the in-game version of events.

It's important to note that the humans do ultimately lose the First War in Warcraft: Orcs and Humans. Will the humans of Stormwind suffer the same fate in the film? That remains to be seen, but such a conclusion would certainly shock viewers unfamiliar with Warcraft lore who expect a happy ending.

Warcraft is in theaters June 10.