A New Model for Free-to-Play 4X Strategy on Mobile

Many of the most successful F2P mobile games of all time, from a commercial standpoint, have been strategy games like Clash of Clans, Game of War, and Mobile Strike. These games provide a distillation of the resource management, base-building, and combat that have defined the traditional PC strategy genre. But whereas many mobile games in the RPG, battle royale, and puzzle genres have matched or exceeded the gameplay depth of their console and PC strategy games, the same cannot be said for the strategy genre.

4X games are some of the most popular PC strategy games today, not least due to their strategic depth, variety of playstyles and victory conditions, and layered gameplay objectives that encourage hooked players to exclaim “just one more turn” until the crack of dawn. As a result, the most successful 4X games can maintain a substantial, dedicated playerbase for a decade or even longer.

Civilization V (2010) Steam Concurrent Players

While 4X-based mobile strategy games do exist, they are few and far between, and they do not capture many of the genre’s most iconic and engaging features. There is a massive opportunity for mobile game developers in identifying how to better translate the 4X strategy genre for mobile devices and audiences.

Defining a 4X Game

At the core of every 4X strategy game are the so-called “4 X’s” for which the subgenre was named. These are:

• eXplore – sending units to unveil the fog of war, in order to reveal territory, resources, and other players

• eXpand – claiming new territory and resources by creating, expanding, or acquiring settlements

• eXploit – gathering and using resources to achieve victory, and improving resource efficiency over time

• eXterminate – attacking and eliminating opposing AI or human players, either for offense or defense

As 4X and other strategy games have increased in complexity, a number of other iconic tropes and gameplay features have arisen, which have since become 4X staples:

• Tech trees – a large series of upgrades with complex interdependencies and prerequisites, encouraging players to select upgrades in the order most appropriate for their objectives, playstyle, and faction

• Diplomacy – the ability to trade resources with other players, form alliances, or commit to specific diplomatic agreements such as defensive pacts or open borders

• Factions – visually distinct empires, tribes, or civilizations providing certain gameplay buffs or handicaps, often including unique units or settlement features, and occasionally changing entire gameplay systems

Despite the fairly narrow definition of 4X games, they do show a lot of variety. 4X games can be real-time or turn-based, use a wide range of potential combat systems, and match virtually any setting. Each game also places more or less emphasis on each of the 4 X’s, and offers a different degree of customizability for factions and units. They can vary substantially in length and difficulty as well.

Aside from the core gameplay features described above, which simply may not interest all players, the 4X genre suffers from a few common complaints, notably:

• Excessive micromanagement of units and settlements

• Long session times, typically with many sessions required to finish one game

• Copious menus and sub-menus, often requiring more than 10 clicks for one action

• A negative feedback loop, in which poor luck or decisions early-on can guarantee a loss

The Galaxy Map view in Stellaris, displaying unexplored stars to the north (eXplore), resources and monthly gains at the top of the screen (eXploit), and an outline summarizing settlements (eXpand) and military fleets (eXterminate)

Current Models of Mobile 4X Games

Blitz Conquest 4X Model

This model is so named for its rapid pace of play and short, one-off matches. After choosing a faction, players start out with a single settlement, and must send military units out to conquer new settlements, while using resources to upgrade their settlements and tech trees. Victory comes from conquering every other player-controlled settlement on the map, and matches generally do not take more than a few dozen turns, or about 15-20 minutes. This model is best exemplified by Polytopia and Hexonia. These are not very lucrative, with Polytopia earning $60k and Hexonia earning $27k in September.

These games basically distill eXplore, eXpand, eXploit, and eXterminate into their core essences, in a version of the 4X genre clearly designed with mobile screens and controls in mind. Although these games are fun and straightforward, their lack of complexity is a double-edged sword. At about 15-20 minutes, a single match tends to be too long for an average play session, but too short to occupy a player’s attention throughout a whole day. Additionally, while visually distinct premium factions can be purchased for real currency, the simplistic gameplay and graphics limit the appeal of these purchases, and one-off matches limit the potential scope of monetization in general.

The player faces off against an AI-controlled enemy (Hexonia)

Hybrid 4X-RTS Model

This model is so named for the combination of 4X features and trappings with the base-building gameplay of persistent real-time strategy mobile games like Clash of Clans. As in most mobile RTS titles, players build a base over an extended time, in a persistent world where hostile players can launch raids to gain resources. However, unlike a typical mobile RTS, the player’s base has a set position in the world map relative to other bases and resource nodes. Players must move their base or uncover the fog of war to find new raid targets and resource nodes, taking distance and travel time into account. This model is best exemplified by games like Rise of Kingdoms and Nova Empire. These are very lucrative, with Rise of Kingdoms earning $24 million and Nova Empire earning $400k in September.

These games basically take a tried-and-true approach to mobile strategy gaming and add a layer of complexity via 4X-inspired game mechanics. As a result, they may draw in strategy gamers looking for new mechanics, but are unlikely to interest any players that have previously given the genre a pass. Unfortunately, given that these games are persistent and PvP-centric, they must sacrifice many of the defining 4X features that add long-term engagement and gameplay depth, such as unique faction-based gameplay, diplomacy, and managing multiple settlements. The lack of 4X features extends to the world map, which can therefore appear as just ‘window dressing’ for in-game raid and resource timers.

4X-inspired world map, including resource nodes and player settlements (Rise of Kingdoms)

Traditional 4X Model

These games are simply existing 4X games ported to mobile devices, such as the Civilization VI port for iOS and Android. They retain the full gameplay of the originals, albeit adapted to fit the touch controls and small screens of mobile. They are moderately lucrative, with the Civ VI port earning $250k in September.

While these games are the most faithful to modern PC 4X titles, mobile games directly adapted from PC tend to suffer major performance issues and bugs, and these are no exception. 4X ports in particular offer no solutions for the micromanagement, long game times, and excessive menus that tend to turn people away from the 4X subgenre. Moreover, they are effectively restricted to pay-to-play monetization systems, which largely do not match up to F2P systems commercially.

Primary game view, focusing on the player’s settlements (Civilization VI - Android)

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How to Better Translate 4X to F2P

Effectively translating the 4X subgenre to mobile, in a way that is more faithful and commercially viable than the models detailed above, is not easy. After all, this isn’t about keeping with the spirit of 4X games for its own sake; we want to capture what it is that makes them so engaging in the long-term. Therefore, it is important to look beyond the surface level, to the ways in which 4X mechanics interact and their real purpose.

Modern 4X games are designed with a particular gameplay loop and progression in mind: acquiring resources, using settlement buildings to transform resources into diplomacy, military power, or research, and then using those outputs to make progress toward one or more victory conditions. Virtually all 4X games offer multiple paths to victory, demanding careful prioritization of resources. What is more, a player’s military, diplomatic, research, and economic strength all reinforce each other; a player must have the ability to research new military units, the diplomatic relations to avoid unfavorable wars, the resources for new settlements, and so forth.

Simply put, a player must make use of all core gameplay systems, to some extent, in order to win. In this regard, 4X is about strategic trade-offs. As a player’s territory grows and they are faced with an ever-increasing array of choices and trade-offs, they will have short, mid, and long-term goals, all in service to the player’s chosen or preset victory condition. With this in mind, 4X is also about layered goals. Any new model of mobile 4X, whatever compromises it makes due to the limitations of mobile, must follow these two principles.

The more modern 4X conventions like diplomacy and tech trees have not always played a role in the subgenre (or the board games that originally inspired it), but they do contribute to the principles of great 4X design. Tech trees are already a common staple of mobile strategy games and some RPGs, and players understand the role they serve as both goals and mechanisms for unlocking new gameplay, so conceptually they should be easy to implement. The challenge with a 4X model is to ensure that a tech tree supports all victory objectives, and contains enough complexity to force trade-offs by players.

Diplomacy is more of a challenge. Resource trading and even more complex types of diplomacy are simple enough when playing against AI. However, due to the nature of mobile multiplayer, which is usually asynchronous, implementing an effective diplomacy system across-the-board may be tricky. Only a few mobile games, such as Conspiracy and Subterfuge (and depending on your interpretation, social deduction games like Among Us), have pulled off PvP diplomacy effectively. Whatever its implementation, it should add an additional layer of intrigue to the game and perhaps even be a viable alternative to combat, in certain scenarios.

A player reviews their messages with several other players (Conspiracy)

In terms of the common complaints levied toward 4X games by casual gamers, it is clear that some of those – notably the long session times, excessive menus, and need for micromanagement – are especially critical. The recent explosion in idle RPGs, including smash hits like AFK Arena and Idle Heroes, is a reminder of the demand for games that simply let the player get to the action as quickly as possible. While 4X is pretty much incompatible with ‘low-effort’ idle gameplay, and unlikely to even draw in the same playerbase, there may be lessons to be learned by idle RPGs’ ability to entertain in both 5-minute and 45-minute sessions.

Proposing a New Model: 4X Within 4X

What no current 4X mobile game has done successfully is encourage both short-term and long-term strategic trade-offs, while maintaining all of the subgenre’s core trappings and variety. This model is designed with these goals in mind.

Here, players engage in one-off, 10 to 15-minute matches where they are tasked with amassing the greatest number of victory points, or eliminating all enemy players. These matches largely follow traditional 4X gameplay, with resource-gathering, exploration, settlement development, and combat as core gameplay mechanics. In this regard, they are pretty similar to ‘Blitz Conquest’ style games, where each match provides unique challenges and the same sense of short-term progression every time.

However, unlocking new units and structures will be done through certain resources or settlement milestones, with no in-match tech tree to speak of. That is where the other half of the model comes into play. In essence, this model combines elements of 4X with suitable mechanics from the ‘hero collector’ model of mobile RPGs.

Every match rewards resources and currency that can be put toward advancing a permanent tech tree, gaining new factions, and unlocking special units or features for each individual faction. These unlocks and rewards can then be used in battle, providing further rewards, and so forth. Players must choose not only what new unlocks will provide the greatest benefit as the matches scale in difficulty, but also which factions and units they find most exciting.

Unlike a persistent strategy game, which must provide an even playing field for each player, individual matches in a 4X Collector can be made as challenging as needed, or geared toward certain factions more than others. Over time, the aesthetic and gameplay differences between factions would give players the same gameplay variety that makes traditional 4X so replayable, ensuring the individual matches remain fun.

The matches themselves will differ from traditional 4X in some crucial, but beneficial, ways. To preserve a lightning-fast pace and retain players who prefer sessions as short as 5 minutes, there will be an option to auto-play matches. Additionally, while this model is largely incompatible with complex diplomacy within matches, factions may have ‘culture’ and ‘diplomacy’ ability unlocks that can grant temporary bonuses or otherwise contribute to victory.

Such a model would have many options for live ops and monetization as well. Short 4X-style matches would enable daily or weekly challenges that encourage players to switch up their gameplay style, and reward resources. In addition, new factions, units, and even match types could be released every few months, under a battle pass system that encourages both spending and engagement. Finally, if the art style is sufficiently detailed, a battle pass system could also offer rare color schemes, unit models, and other cosmetics.

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Given the popularity and longevity of 4X strategy games, it is no wonder mobile developers are beginning to delve into this subgenre. However, judging by the commercial performance of most 4X mobile games so far, there is clearly an opportunity in pushing for new models that better capture what has made the subgenre so successful. As we see new mobile RPGs like Genshin Impact set a new bar for graphical and gameplay quality, and see tremendous gains as a result, perhaps a mobile strategy game taking the best cues from the 4X subgenre will be the next to catch the industry by storm.