A True MMO RTS on Mobile with Unity 5
Published 4 years ago
How we used Unity 5 to create the units, game mechanics, and a massive meta game in War Commander: Rogue Assault
Common Approach to Scale 
Massively multiplayer mobile strategy games require thousands of hours of compelling play to retain and engage players over many years. Most mobile strategy MMOs address this demand with simple art styles, a few 2D game pieces, and very basic game mechanics.
Reaching Beyond
On War Commander: Rogue Assault, we wanted to go way beyond common mobile approaches by creating a fully 3D realistic art style typical of high end PC games, articulated animated pieces players control, and a rich PvE meta game that required hundreds of hand crafted arenas to satisfy the diverse game mechanics.
War Toys
War Commander: Rogue Assault’s units are each modeled based on real units used in modern wars.The units are rigged and animated in Maya then imported into Unity using a custom asset importer tool that we created. We import the 3D model, texture, portrait, rig, and animation to articulate the units on the battlefield. We ensure that units only see and fire on objects their realistic models will allow through their rig. Ray casts are made when a unit is targeting an enemy unit or structure to determine line of sight. Non-visible 2D proxy collision meshes are used to improve performance and allow for some leeway to keep the game accessible and fun while giving the impression of complex 3D collision geometry.  We also use ray casting to physically move projectiles through the environment, again ensuring the visual effect of the missile or bomb matches the in-game result.
Unity UGUI allows players to not only create squads through a sophisticated UI, but also select these squads of units in battle with a tap. Ray casting into the scene for collision allows us to determine a squad or building has been selected, and allows the player a high level of control. Atypical of most mobile games, players can actually tap on units at any time during the battle and redirect them. Unity 5 gives us the core tools needed for Rogue Assault’s players to exercise their skill with a much higher degree of control on the battlefield.
Variety is the Spice of War 
We found that once players could direct individual squads of units at any time, they really craved a variety of mechanics to allow them to customize their style of play. Unity 5 tools enabled our design and art teams to deliver in a big way with 23 units at launch and a plan to deliver new units monthly.
Instant, Wide, and Deep
The decisions to go wide and deep with units resulted in our desire to go wide and deep with the bases players would be destroying with all these cool units. Like many games, players create bases that other players attack. Unlike most games, building in War Commander: Rogue Assault is instantaneous, and players can rearrange their bases at any time. The ease of base design, wide variety of units, and constant attacker control of units required a wide variety of base defenses resulting in an endless variety of player-made bases to attack. KIXEYE engineering built a series of custom tools that enabled our design team to create hundreds of bases, create amazing scripted behavior, and detail thousands of miles of world map. The Unity 5 asset store was a huge help where we found camera sequencers for our in-game cutscenes, tweening tools for our animators, and many other very useful tools. Our custom Unity 5 tools allow our design team to convert Excel files into JSON files for inclusion in the game client or for access by our game servers. Multivalent testing from a server push gives our team the ability to refine game balance and other UI / UX in live conditions, without taking the game down and without requiring app upgrades.
War Stories
To ensure players can learn as they play, we decided to create full single player campaigns with designer crafted bases that teach core mechanics and give players a chance to preview new units to discover their individual strengths and weaknesses. Again the Unity 5 framework assisted our team in creating custom base editing tools and game scripts to craft rich content complete with VO, localized text in many languages, and detailed mission briefings.  All of this content is downloaded in bundles and loaded at runtime reducing initial download times and minimizing the app memory consumption on devices.  Keeping the initial app size under 100 megabytes is a critical task for our team in each release.  We never want a player to require a wifi connection to download any KIXEYE game.
World Piece
Over the course of developing War Commander: Rogue Assault, it also became clear that the wide diversity of units and nearly infinite variety of player bases required something more than a simple world map where players would typically park their base in a hive and have minimal interactions. The Rogue Assault team took on the task of a massively scalable world built on true geographical data for the war-torn areas of western Europe and north Africa. Each player earns the ability to deploy numerous Forward Operating Bases (FOBs) that affect combat in the world map’s War Zones. FOBs can add artillery strikes to soften an opponent by destroying clumped defenses, bring reinforcements in as defenders in the middle of a battle, or block advancing players with reinforced bunkers. The addition of a simple and rich meta game gives War Commander: Rogue Assault alliances a deeply engaging game with organic overtones on our world map. Unity 5 offered us the tools to create the bases, game pieces, and visual effects that expand our game into a persistent conquest for world domination.
John Getze