XCOM was the surprise hit of 2012: an in-depth, difficult strategy game that managed to score mass appeal, even winning Game of the Year awards from major sites like Kotaku and Giant Bomb. A turn-based strategy game! But developers Firaxis did a sensational job of taking the vast majority of the classic series’ depth and adapting it to be much more accessible.

Over three years later, and the inevitable sequel is on the verge of release (February 5, to be precise). But it’s not going to take anyone by surprise: XCOM didn’t just score Firaxis a hit, it created an entirely new subgenre of games.

But first, what do we mean when we talk about games like this? There are three major components, and all of these games have at least two of them.

The tactics of 'XCOM'

Combination of strategy and tactics: XCOM is divided in half, with some time spent managing the alien invasion of the entire planet, and the rest in the individual battles. Mess up one of these, and you’re doomed, now matter how smart you play the other.

Straightforward-but-complex combat: In tactical combat games, character movement through space is the most important consideration, and character skill in more important than player skill (that is, you win by playing smart, not by clicking more or aiming faster). The key innovation of XCOM compared to other tactical games, whether Japanese or Western, was simplifying this, breaking each character’s turn into two actions, instead of dozens of action points. It was simple, but it made sure the game was always about interesting choices.

The potential for disaster: The neat thing about XCOM was that you could take a group of soldiers, customize them, improve them, become attached to them, and then watch them all die in a hail of alien plasma. It’s fun! Games rarely allowed for that level of brutality: Death in RPGs was pre-scripted; death in strategy games comes in faceless “units”; and “roguelikes” — the genre most famous for permanent character death — almost always was based on individual characters. XCOM could have bodies on top of bodies, even in relatively successful campaigns.

When 'XCOM' meets 'Game of Thrones' every mission is a Red Wedding waiting to happen.

(I customized my squaddies to be Game of Thrones characters; and ended up with an accurate body count. But this was before an actual “XGOT” came out.)

Today, we’re rounding up the best games that, although created in the wake of the original XCOM, are now its sequel’s biggest competitors.

Massive Chalice

The formula: XCOM meets Game of Thrones

In Massive Chalice you control a kingdom of noble houses fighting off an implacable supernatural invasion. You marry lords and ladies, have and adopt children, train them, send some to do research and some to fight, and retire them to have more babies to fight a war spanning hundreds of years. This sounds crazy ambitious, but using the XCOM strategy/tactics model makes it work in reasonably clear fashion. Battles use the XCOM two-move system and end up fast and satisfying. Add in a surprisingly effective high-resolution/low-poly art style, and Massive Chalice is a real winner.

Invisible, Inc.

The formula: XCOM meets The Bourne Identity

Stealth games never really clicked with me. I can definitely like them, in cases like Dishonored, but the genre inspires a level of love I don’t entirely understand. Well, I didn’t until Invisible, Inc., a turn-based tactical sneaker, where you control a small group of agents on a series of escalating heists to try to save their asses. Everything about Invisible, Inc. escalates quickly, taking what looks like smooth, controlled missions and turning them into desperate battles against chaos.

With rare character death, a fast-paced — although quite difficult — campaign, Invisible, Inc. may be the least XCOM-like game on this list, but it’s still walking the trail XCOM blazed.

The formula: XCOM meets XCOM multiplied by XCOM

Sure, the 2012 XCOM was good, but it had a fundamental tension: It couldn’t decide if it wanted to be a strategy game or a role-playing game. Should you take a few core characters through the entire journey, or should you expect huge casualties over the course of the alien invasion? Long War was a group of modders’ answer to that question: It’s a more strategic version of XCOM, built on managing a military machine instead of guiding a small party.

Everything’s bigger in Long War. You start with 40 squaddies instead of a dozen. You can take eight of them into battle instead of just six. Fighters can actually get shot down attacking UFOs. Aliens build bases all over the world instead of just the one. It even adds accented voices, so you can get English-speakers with British accents! Long War basically takes everything good and bad about XCOM and doubles it. Which is great, up until the endgame, which turns into even more of a slog. But if you can’t get enough XCOM, well, Long War sees that as a challenge.

Hard West

The formula: XCOM meets Jonah Hex

Hard West is probably the game most focused on adapting XCOM’s tactical systems of any of these. It’s married to the two-action combat system, but adds in a bunch of “Weird West” quirks and systems. The most interesting of them is “luck,” which turns into a resource that players can manage instead of being just a dice-roll inside the computer. Every time a shot misses a fighter, his or her luck goes down, until the next one is a guaranteed hit. Or luck can be used like magic to make trick shots.

Hard West takes its grim plot line a little too seriously, and it has the weakest strategic mode of any of these games. But it also has music from The Witcher 3’s Marcin Przybyłowicz, as well as really neat ideas about transferring the Western into the video game realm.

Xenonauts

The formula: X-COM (the 1994 game, with the hyphen). Just like X-COM.

Not every fan of the original X-COM was happy with the 2012 reboot’s simplicity. For them, there’s Xenonauts, an homage to the original classic, and a game built on the idea that you can never have enough action points. It’s the only game here I haven’t played, but it’s worth mentioning as an example of what the genre might look like without the 2012 XCOM.

Darkest Dungeon

The formula: XCOM meets Cthulhu and flips on its side

If XCOM 2 is a great game, it’s still going to be playing catch-up to the superb Darkest Dungeon in the Game of the Year race. I wrote about why Darkest Dungeon is so special recently, and all that is true.

But it’s also the game that seems to capture what made both the original X-COM and the reboot so special, even though at a glance, it looks much more like a traditional role-playing game. It’s tense, filled with tough decisions, and the tempting but unrewarding option to flee is always present. Its dungeons present a much more comprehensible challenge than XCOM’s occasionally muddled missions. And the cleverness of using sanity as both an overarching aesthetic theme and an actual game mechanic ties the game together at a level that surpasses most all of its peers.

As for XCOM 2? We’ll find out how it fits in here when its reviews are unveiled and the game is launched in early February. But it’s gonna have a lot more competition than a tactical game fan could have dreamed before 2012.