Hey Civ fans, Sarah here! For our last Dev Diary of this year, we've got one that many of you have probably been waiting for – a deep dive into combat! Authored by Senior Game Designer Brian Feldges, this Dev Diary will go over the history and role of combat in the Civilization franchise, talk about the impact being brought by our exciting new Commander military unit, and additional improvements being made for combat in Civilization VII.

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Hello Civ community! My name is Brian Feldges. I have been working on the Civilization series in one form or another since I started at Firaxis back in 2006, but my first credit as a designer began when we started working on Civilization VI. I've always had an affinity for wargames so at the time I was more than excited to immerse myself in the military and combat gameplay systems for Civ VI. Today, I'm excited to share all of the changes, improvements, and new features coming to Civilization VII's combat, and also outline a bit of our general design philosophy. 

Military conflict has always been a central component of the Civilization series and has remained as one of the main victory types since the series' inception. Even if you don't plan to conquer the world with your military might, a good army and an understanding of combat basics are important as you still need to be able to defend your civilization from rival powers and ambitious Independent Powers.

A Bit of History

The way war is waged in Civilization has changed throughout the series' history. Originally, players could stack multiple units in a single map tile – known by the community as "stacks of doom" – and battles were fought by clashing these stacks together. After unit strengths were compared and a bit of random "dice rolls," a winner was determined and the result was often the defeat of an entire enemy army in one fell swoop. 

The release of Civilization V brought some big changes, including the switch from square tiles to hexagons and the introduction of a "one unit per tile" rule for combat. This added a new layer of depth to combat, shifting it away from the "stacks of doom" that dominated the battlefield toward a more tactical approach. Different types of units still had many of the strengths and weaknesses as before, but now battles were fought in a series of single unit vs. unit combats, spread throughout the map. Players could strategically place units based on movement and terrain, and take advantage of ranged attacks to soften up their enemies before moving in to engage in melee combat. 

This combat design continued in Civilization VI, but there were some side effects in switching to one-unit-per-tile. "Stacks of Doom" became replaced by "Carpet of Doom," where the map would often get congested with units, especially in the late game. This called for some slight design changes, like giving players the ability to join units together in a single hex, allowing for the safe escort of defenseless units like Settlers and Workers, or by joining combat units of the same type into a single stronger version of itself. 

Nevertheless, traffic jams would still occur and moving an army of units from one map location to another could be a cumbersome and time-consuming endeavor. So with Civilization VII, we aimed to introduce several new changes to the military and combat systems, improving on our previous designs and providing some new and interesting gameplay opportunities.

Commanders

The most prominent change to Civ VII combat is the introduction of Commander units. These powerful military leaders have the unique ability to pack nearby units into a single "stack." Units stacked together with a Commander benefit from its movement bonus, allowing for faster relocation to where they're needed. Upon arrival, the Commander's army unpacks, deploying units to adjacent tiles, ready to attack enemy forces, lay siege to cities, or defend territory. 

Commander units are distinct in that they are the only units capable of gaining experience and unlocking promotions. This marks a shift from previous Civ games, where individual combat units could earn promotions. Commanders gain experience primarily through battle involving nearby troops, and their promotions grant a variety of buffs and bonuses – whether that's raising the combat strength of units within their Command Radius to gaining more Yields when stationed in a City's district.

Just having a Commander unit on the battlefield gives you an edge in combat; having an experienced Commander lead your forces is essential for military-focused players. Commanders are even Ageless; throughout the game, they retain all experience and promotions earned in past Ages, ensuring their continued dominance on the battlefield. 

The range of promotions a Commander can earn is vast, encompassing multiple themed "discipline" trees. These allow players to spec their Commanders in different ways by deep-diving into a single tree or spreading their proficiency across multiple trees. There are unique types of Commander units for ground, naval, and aerial combat, each with a slightly different set of discipline trees. For Army Commanders on the ground, their discipline trees are: 

• Bastion: Defensive bonuses, aimed at keeping your army healthy when attacked
• Assault: Offensive bonuses, designed to give you an edge when taking the initiative
• Logistics: Operation-focused bonuses, enabling you to increase the size of your army and more
• Maneuver: Bonuses that focus on movement, making it easier to navigate the map
• Leadership: Bonuses that focus on the Commander unit itself, reinforcing your impact on the battlefield

In addition to making combat units more effective in battle, Commanders also have the ability to use special actions to order multiple units within a Command Radius at once. These include attack orders, which come with an additional combat bonus, as well as orders to heal, repair, or start digging fortifications. Similarly, you can use a packed army to overrun weaker units, negating the need to deploy and fight separately. 

Finally, Commanders streamline your ability to conduct military campaigns from a distance. Battles seldom come without casualties and players often find themselves needing to bring fresh units to a battle or particularly challenging siege. Shuffling replacement units to the frontline can take time and distract from the battle at hand, so we introduced the ability for Commanders to request Reinforcements, automating the process of bringing new units to their location to join the fray without requiring the player to manage each unit's movement individually.

Altogether, Commanders add a new dynamic to combat and greatly reduce the amount of micromanagement needed from the player. We're looking forward to seeing how you utilize these powerful units in your campaigns to come!

Siege Warfare

In Civilization VII, Settlements now sprawl beyond the City center with the addition of Urban Districts (see Edward Zhang's Managing Your Empire Dev Diary). Thus, changes to our siege mechanics have been updated as well.

From a defensive perspective, players can fortify their Cities by constructing walls around their Urban Districts and building special military Buildings or Wonders. In order for an attacking force to take the Settlement, they need to conquer and control each of these tiles before taking the City center. On the flip side, destroying walled districts and occupying them will cede control of that District to you, depriving the defender of any yields or benefits. 

Because of these changes, the pace and difficulty of taking a Settlement varies greatly and adds a wrinkle of strategy in how you expand your empires. If you choose to build rapidly and not invest in any defense, you may find it difficult to maintain control of Settlements on the frontier of your civilization. If you want to take over a fortified Town or City, you'll likely need to build siege units who specialize in taking down walls. You'll even have to think about your Towns and Cities settled on Navigable Rivers; naval forces can sail inland and capture Settlements, if you don't defend them properly. 

Improved Visual Battlefields

One of the characteristics of one-unit-per-tile combat is that battles happen one-at-a-time, with each unit attacking and defending in turn. Typically, this means that on your turn, you attack some enemy units – often not resulting in outright destruction – and when it's not your turn, the same thing happens to you. 

Visually, this was shown where the attacker moves forward to engage, performs a battle animation, and then returns to their original position. Watching multiple units do this in sequence can sometimes look comical, like a group of bad guys waiting their turn to attack the protagonist in a cheesy action movie. A game journalist once likened combat in 4X games to a hilarious Monty Python sketch, where a man prances forward, slaps another man in the face with a fish, and prances back. I couldn't help but laugh at the truth in that comparison, as it was something we had noticed as well. Still, it was a necessary presentation of the way we've so far handled combat in Civ games.

It was around that same time that our Units team asked whether we needed to have the unit stop fighting and move back to their hex at all. What if, even though the combat was already resolved in the game, we just allow the units to continue fighting until one of the units is destroyed or the game turn ends? This quickly turned into one of those moments where function follows form and sparked a change in the way we handle combat flanking mechanics in the game. 

In past Civ games, we never introduced any sort of unit-facing mechanics that you often find in strategy wargames, meaning it didn't particularly matter what direction you attacked or were attacked from. Direction of attack matters if you want to simulate flanking, but we thought details like that were too fiddly for most Civ players, who already had to think about managing their empire on so many different scales.

With the game's overall reduction in micromanagement and our desire to support the Units team's idea of continuous combat visuals, we felt comfortable in implementing proper flanking bonuses – without requiring the player to designate a specific direction each turn. This means that you don't have to pick a direction before battle; engaging an enemy automatically locks the two units toward a front. And now that they have a front, you can attack from the sides and behind. Having continuous combat is a win/win for both the Unit team and for combat design in Civilization VII.

Finding Balance

Part of the appeal of Civilization is that it's a game made up of many different systems, all working in concert to represent the epic scale of managing a historical civilization. When you work on Civilization, you quickly learn that if there are ten Civ players in the room, you get ten different opinions on which part of the game is the most fun. 

Every player is different, and not all players enjoy the military part of the game as much as others. As I mentioned earlier, combat has always been a necessary part of building and managing your empire. For game designers, our challenge is to create a combat experience that is both fun for players looking to dabble in skirmishes, while still offering enough depth and reward for those pursuing a full-scale military campaign. 

Finding that balance is always tricky, but we think we have something special with all of the new features, adjustments, and changes introduced in Civilization VII. We look forward to seeing what strategies and tactics you use to conquer the world, or successfully protect your empire so that it may stand the test of time!