As we've already established, Metal Gear is host to one of the longest-running, interconnected storylines in all of gaming. It's a series that basically requires some prior knowledge going in — then again, Metal Gear doesn't necessarily make it easy.

Case in point: there are no less than four characters who have used the codename "Snake" at one point or another throughout the series. Some are villains, others are heroes, one is a mixture of both — it's downright confusing, especially for fans who are trying to dive in for the first time.

Don't worry, we've got your back: that's exactly what this guide is for. If you've ever wondered what the difference between a Liquid and Solid Snake is, or who this "Big Boss" guy is, this is the guide for you.

A quick note: due to his extremely brief tenure as "Snake" and general whininess, we've chosen to omit Metal Gear Solid 2: Sons of Liberty's Raiden from the list. Oh, and SPOILERS AHEAD!

Big Boss

Real Name:
• John, a.k.a. Jack
Other Aliases:
• Naked Snake, Punished Snake, Venom Snake
First Appearance:
• Metal Gear (MSX)
Appeared in:
• Metal Gear Solid 3: Snake Eater
• Metal Gear Solid Portable Ops
• Metal Gear Solid: Peace Walker
• Metal Gear Solid V: Ground Zeroes
• Metal Gear Solid V: The Phantom Pain
• Metal Gear
• Metal Gear 2: Solid Snake
• Metal Gear Solid 4: Guns of the Patriots

While he may have originally debuted as the final boss in the original Metal Gear, Big Boss isn't your standard video game villain — in fact, over the course of the past several games, Big Boss has become the focus of the series.

Big Boss wasn't always Big Boss — at first, he was Naked Snake. During the events of Metal Gear Solid 3: Snake Eater, Big Boss would become the legendary soldier featured in the original game — but not without cost. As a part of his mission in Russia, Big Boss was forced to execute his mentor — this would sow the seeds of distrust within him, and over the years, Big Boss would slowly turn from hero to villain.

Even after his supposed death at the hands of Solid Snake during Metal Gear's finale, Big Boss managed to influence many of the events throughout the series, including the Foxhound rebellion that the original Metal Gear Solid was based on.

Now, he returns as the protagonist of Metal Gear Solid V: The Phantom Pain, leading a group of mercenary soldiers known as Diamond Dogs. According to series creator Hideo Kojima, this is the missing link between 2010′s Metal Gear Solid: Peace Walker and the original Metal Gear — meaning that it's highly likely that fans will finally see Big Boss transition from tortured hero to ruthless villain.

Solid Snake

Real Name:
• David
Other Aliases:
• Old Snake
First Appearance:
• Metal Gear
Appeared In:
• Metal Gear
• Metal Gear 2: Solid Snake
• Metal Gear Solid
• Metal Gear Solid 2: Sons of Liberty
• Metal Gear Solid 4: Guns of the Patriots

From the very beginning, Solid Snake has been the hero of Metal Gear. Debuting alongside Big Boss in the original game, Solid Snake quickly became one of gaming's most iconic heroes and continues to be one of the industry's most recognizable characters even after his story came to a close.

Even at a young age, Solid Snake was considered to be one of the greatest soldiers of the modern era: Snake was incredibly intelligent, fluent in multiple languages and highly skilled in hand-to-hand and ranged combat. However, all of this was expected of him — he, along with his two "brothers," were actually clones of Big Boss. Snake was the perfect soldier by design.

Over the course of the franchise, Snake would go on to defeat Big Boss, his own cloned brothers and several different versions of Metal Gear itself. By the end of Metal Gear Solid 4: Guns of the Patriots, Snake was an old man — the work of his genetically-modified body's accelerated aging. Despite the absolutely ridiculous odds stacked against him, however, Snake would go on to live out the rest of his days in peace.

That's not to say Snake won't make another appearance: speculation surrounding the character "Eli" from The Phantom Pain suggests that Snake and his fellow clones could appear in the upcoming series finale ...

Liquid Snake

 Real Name:
• Unknown
Other Aliases:
• N/A
First Appearance:
• Metal Gear Solid
Appeared In:
• Metal Gear Solid
• Metal Gear Solid 2: Sons of Liberty (as Liquid Ocelot)
• Metal Gear Solid 4: Guns of the Patriots (as Liquid Ocelot)

At first glance, Liquid Snake may be the one-off villain of the original Metal Gear Solid — in truth, Solid Snake's clone brother has had quite a bit of influence over the years.

In many ways, Liquid Snake is the mirror image of Solid Snake — both are legendary black ops soldiers, both are incredibly intelligent and both are clones of the legendary Big Boss. However, if there's one thing that Liquid has that Solid doesn't, it's an inferiority complex.

Solid and Liquid may be clones, but they're not 100 percent copies of Big Boss (that comes later). As a result, Liquid always thought of himself as the "inferior" clone — when Solid Snake managed to kill Big Boss, said complex only grew worse. It was then that Liquid decided to take command of Foxhound, steal Metal Gear REX and threaten an attack against the United States. Of course, he was defeated by Solid Snake during the events of Metal Gear Solid.

Liquid's legacy didn't end there, however: in an effort to fool the Patriots into lowering their defenses, recurring villain Revolver Ocelot fused Liquid's arm onto his own and underwent intense psychological manipulation in order to implant Liquid's personality onto his own (Metal Gear Solid gets kind of weird from time to time).

Also, as previously stated, there's a chance the Liquid and Snake may make appearances in Metal Gear Solid V: The Phantom Pain ... though there's no way of knowing for sure until the game is released.

Solidus Snake

Real Name:
• George Sears
 Other Aliases:
• President of the United States
 First Appearance:
• Metal Gear Solid 2: Sons of Liberty
 Appeared In:
• Metal Gear Solid 2: Sons of Liberty
• Metal Gear Solid 4: Guns of the Patriots (as a corpse)

There's a black sheep in every family, even one as messed up as Big Boss' — and in this case, said honor goes to Solidus Snake.

If Liquid and Solid are meant to be two sides of the same coin, then Solidus is basically both sides of his own coin. Created to be a perfect replication of Big Boss, Solidus was the third and final clone of the legendary soldier. However, instead of being a war hero like his brothers, Solidus (using the name George Sears) went into politics, eventually becoming the 43rd President of the United States ... and the Patriots' puppet.

Throughout his Presidency, Solidus helped further the Patriots' goals of information control across the world. At the same time, however, Solidus grew to loathe the Patriots — as such, he put the events of Metal Gear Solid into motion. When Liquid failed, Solidus took matters into his own hands — by hijacking the Big Shell oil facility (and the Arsenal Gear warship hidden underneath it), Solidus planned to fight back against the Patriots' control. Unfortunately for Solidus, he was stopped by the combined forces of Solid Snake and newcomer Raiden.

After that ... well, Solidus stayed dead. Aside from holding the genetic key Revolver Ocelot needed to expose the Patriots, Solidus' use throughout the rest of the franchise was limited to giving up body parts in order to build Big Boss a new body. Basically, the only mention Solidus got after dying was a mention during a cutscene in Metal Gear Solid 4: Guns of the Patriots.

With this guide, you shouldn't have any more trouble keeping track of which Snake is which — but that's just the start. If you want to know everything that's happened throughout the first half of the Metal Gear timeline, we've got a detailed timeline that should help you sort everything out.

Of course, there's also a little game called Metal Gear Solid V: The Phantom Pain — the latest in Hideo Kojima's stealth-action series is due out on Sept. 1.

Be sure to follow T-Lounge on Twitter and visit our Facebook page.