Real-Time Strategy Game Mechanics

Published February 23, 2009

Developer Ensemble Studios dared to ask what would happen if they brought their years of real-time strategy (RTS) expertise to bear exclusively onto an Xbox 360® game. Where would the game design take them, how would the mechanics evolve, and how would the game's flow and tactics break from tradition?

Covenant on the move.

The answer to all these questions is Halo Wars™, set for release March 3 and poised to bring console gamers and the real-time strategy genre together at last. Certainly, the ingredients are there: the much-loved franchise, a world and conflict already primed for a real-time strategy approach, and a fan base eager to engage in a Halo adventure in a new and unexpected way.

Vehicles fare best against infantry, infantry can
outduel aircraft, and aircraft can shred vehicles.

Behind the drama that drives the Halo Wars Campaign, cooperative play, and multiplayer offerings, is the set of game mechanics. It's these controls that Ensemble hopes will elevate Halo Wars beyond previous RTS games, with its commitment to accessible control without sacrificing deep tactics.

Unit Selection

Reliable and flexible unit selection may be the real-time strategy genre's most important mechanic, and here Halo Wars doesn't disappoint, featuring four distinct and important ways to group your units.

1. All units: Tap LB to select every available unit on the entire map simultaneously.
2. Local units: Tap RB to select all on-screen units.
3. Unit specific: Highlight a unit and double-tap to select every unit of that type.
4. Paintbrush: Hold down A to access a circular "paintbrush," which you can then use manually to group units together.

Ready the Vulture's Missile Barrage.

Whether you're using the paintbrush to split up armies to send them on the attack from two different angles, or whether you're ordering a mass retreat for all units when your main base comes under threat, these four unit selection techniques should give you all the flexibility you need to be employed within a few short seconds.

X and A

Once your desired units are selected, it's easy to move and command them. In most RTS games, the command for selection and movement is the same (such as the A button), but Halo Wars has broken up these commands, with X moving units, commanding them to attack, or executing a context-sensitive order. The A button is used only to select units. This way, you don't accidentally send units you've previously selected scurrying off somewhere while you're trying to select a new unit.

D-Pad Porting

If troop selection and movements sit atop the list of high-priority RTS controls, moving about the map quickly and efficiently is a close second. Although you can scroll across the map with the Left Thumbstick (and do so quickly with the Left Trigger and Left Thumbstick in tandem), Halo Wars is designed with the D-pad in mind for quick, tactical movement. Here's how it works:

• Left: This cycles you through each of your operational bases.
• Right: This moves you to the latest alert location. For example, if your traveling units are ambushed, pressing right will take you directly to their location.
• Down: This cycles you through each of your various created armies.

Scarab sighted! Northwest corner!

Right Trigger

While commanding entire platoons is great for troop movement, it's important to have access to unit-specific commands when the bullets start to fly. In Halo Wars, the Right Trigger is used to cycle through your individual units without sacrificing control of your army.

For instance, let's say your army clashes with a widely varied enemy force. Units must be ordered to attack enemies that they're strongest against. Quick use of the Right Trigger will have your Warthogs running over Grunts, your Flamethrower squads engaging Hunters, your Spartans jacking enemy vehicles, and your anti-air Wolverines blasting Covenant Banshees out of the sky.

Once you're done issuing unit-specific commands, tap B to regain full control of your entire army.

Special Attacks

Every unit exists for a purpose, but beyond their general strength against specific enemies, most units also have a Special Attack. Standard marine infantry can toss grenades or fire off RPGs, Flamethrower platoons can stun enemies with flashbangs, and Hornets can unleash a missile barrage. Execute these Special Attacks by pressing Y when you have a unit selected, and an enemy target in your sights.

Rock, Paper, Scissors

Like any good strategy game, every unit in Halo Wars has its own set of strengths and weaknesses. While the following formula doesn't take into account all the subtleties and upgrades for each unit, remember the following: vehicles fare best against infantry, infantry can outduel aircraft, and aircraft can shred vehicles.

New base incoming.

Base Simplicity

Other real-time strategy games feature a wide variety of buildings and you must order their construction manually, but Halo Wars gives you a core base with a set number of building sites from which to build whatever structures you desire. This includes Reactors (needed for technology), Supply Pads (needed to produce resources to build units and structures), Barracks, Field Armory (provides upgrades), and much more.

While you can expand your base up to Fortress level, which offers seven building sites and four turret locations, the limitations placed on how many buildings you can wield at once helps drive your strategy. Sacrifices must be made depending on how you want to build your army.

For example, if you love investing in high-end technology, give up the space normally reserved for a Supply Pad in order to build enough Reactors. Or, if you want to rush the enemy with a large force, give up on the Reactors for extra Supply Pads and a second Barracks.

While you can build secondary bases on the map to supplement your primary base, they can only be built in pre-designated locations on the map. Beyond simplifying the base-building and base management, this approach also helps keep matches balanced and moving fluidly. If your opponent can't build wherever he wants, you don't need to worry about tracking down a single base in some remote corner of the map to finish them off.

Yeeee-ha!

Reactor Upgrades

Technology plays a crucial role in any Halo Wars battle, but in order to gain access to unit upgrades or even just more powerful units, you must invest heavily in Reactors. Build one Reactor and gain access to Spartan units, but build four Reactors and you can call on the mighty airborne Vulture super-unit. And, while you may be able to upgrade your Marines with New Blood in the early going, four Reactors are needed before you can train your Marines to become elite ODST platoons (provided you have Commander Cutter as your Leader).

Population

Your army can grow only so much in size before it's maxed out in Halo Wars, and with different units taking up different population amounts, it takes a delicate, strategic approach to make the most of the population limit.

Initially, both Covenant and the UNSC population limit is thirty. While infantry like Marines and Grunts take up only one population for each unit, more powerful units like Hornets and Scorpions take up two and three population respectively. Use upgrades on either side to increase your total allowed population.

Spirit of Fire

The Spirit of Fire command ship—available when playing the UNSC—provides support to the ground effort from high above in orbit. Tap up on the D-pad at any time to access the Spirit of Fire menu, which includes the following benefits:

That's bad times for the UNSC, I'm afraid.

• Heal: Call on this power to heal any units or buildings in a large area.
• Transport: Order the Pelican drop-ships to pick up entire armies and transport them swiftly to your location of choice. This is particularly useful for setting your troops down in areas they couldn't otherwise reach.
• Disruption: Call on a Disruption Bomb from the Spirit of Fire, which effectively neutralizes a Covenant Leader's Special Ability within a set radius.
• High-powered attacks: Depending on which leader you've chosen, you can call down a Magnetic Accelerator Cannon (MAC) Blast for a devastating, small radius attack, a more widespread but slightly less damaging Carpet Bomb, or a Cryo-bomb to flash-freeze any units caught in the blast zone.

Covenant Differences

While the bulk of the game mechanics work the same for both UNSC and Covenant forces, the purple-clad have a few special differences.

• Leaders: Rather than rely on the Spirit of Fire command ship, the Covenant place their faith in one of three leaders: Prophet of Regret, Arbiter, and Brute Chieftain. Each leader wields a devastating Special Attack. The Prophet of Regret razes single targets at alarming speed with his Cleansing Beam, the Arbiter unleashes an extended Rage attack, and the Brute Chieftain summons forth a Vortex that sucks enemy units in before exploding for massive damage.
• Ages: Instead of building Reactors to increase technology, the Covenant research new Ages in their Temple to gain access to special abilities and more powerful units.
• Gravity lift: A gravity lift sits outside each Covenant base, sending any unit that activates it directly to the Covenant Leader's current location, making rushing and surprise attacks a Covenant specialty.

With these game mechanics, Ensemble Studios has arguably gone farther than anyone else in legitimizing real-time strategy as a viable console genre, and demonstrating the commitment to evolving that genre to fit the needs of the console and the desires of its players.

Article by Ryan Treit