Company of Heroes Designer Diary #2 - Using Cover in a World War II Game

The upcoming game Company of Heroes will combine impressive graphics and physics technology with advanced AI and highly streamlined strategy, with one of the most important conflicts in history as the backdrop. This World War II real-time strategy game will model the chaos of war by including highly interactive environments with destructible objects and terrain, like patches of earth that can be bombed out into craters (which can be used for cover by foot soldiers), and buildings that can be breached, damaged, and torn completely apart by bombing runs, artillery fire, and well-placed explosives from your team's demolition expert. In this second designer diary, staff members from developer Relic Entertainment expand on how the environment will affect the game.

Environmental Strategy, Part Two - Breaking Down the Walls

By Relic Staff

In this next installment of our Company of Heroes designer diaries, we're going to talk about buildings. We'll discuss how to use buildings effectively in combat, and how to take out buildings effectively.

When we set out to create our new vision and engine for Company of Heroes, having fully destructible environments would be crucial. The building system we wanted to create needed to feel real; to be a prominent part of gameplay and feel as organic as the rest of the environment.

This was our vision: When we planned the environmental strategy aspect of Company of Heroes, we knew from the start that the buildings in the game had to meet the core goals of the system. Buildings needed to be destructible in a way that looked believable, and in a way that genuinely affected the gameplay. Rather than spoon-feeding players preset tactics to use with buildings, [environmental strategy] would challenge them to devise their own strategies from basic principles. This emergent gameplay would keep the game fresh and fun, and reward "thinking outside the box," so to speak.

In terms of technology, we knew from the outset that to meet these goals, we'd need a very sophisticated system that went far beyond anything that existed in previous games made here at Relic, and indeed in advance of just about anything in the history of computer games.

We were given the task of helping with the design of our game's destructible building system, and with creating a set of software tools that let our talented artists generate buildings to fit that system. Our final design divided buildings into pieces, each of which could be damaged in seven different ways. That meant that even for a typical building consisting of about 60 sections, there will be an exponentially huge combination of possible damage scenarios. It's a lot of damage states, and it means that when you're playing Company of Heroes, you're unlikely to ever see the same damaged building twice.

However, there's a lot more to it than just creating damaged buildings that look believable. We also had to fully integrate them into the game's physics system to let them interact with the rest of the world. Our physics system can recognize the cumulative damage inflicted on buildings as the game progresses. As a result, you'll actually be able to see enemy soldiers being blasted out of the gaping holes in walls and landing crumpled in the street, or falling to their death when the floor is blasted out from under them!

Buildings also had to work with soldiers' artificial intelligence, so that soldiers could understand the changing state of the buildings through the game and react accordingly. When you see soldiers move to fire from new damage holes in a building during a firefight, you're watching this AI in action. Procedural animations were generated for the final collapse of buildings, to be used once the damage to them was assessed to be critical. It's satisfying to see that enemy sniper's nest crushed under tons of falling rubble!

Let's talk about how buildings will affect your actual strategy in Company of Heroes, because they'll definitely be important strategic considerations. To be successful, you must understand how to use them, and how to deny them to your enemy. Overall, as a player, you should think of buildings like you would in the real world: objects with walls that provide firing positions (and cover). How you interact with each one will depend on your needs and strategy.

You'll most likely want to order your men to garrison buildings. This is an excellent choice for heavy machine gun teams and snipers. You'll want to take advantage of the cover provided, and utilize the excellent line-of-sight that buildings provide. Once you do, you can set up killing zones devoid of cover outside, and divert your enemy into those zones with wire and mines. (You can even deliberately damage part of a building to create firing positions that didn't exist previously!) To help with your war effort, you can convert any building into a temporary barracks as a staging point for fresh troops coming into the battle. Of course, you'll want to remember to order your men to get out if their building is being horribly damaged and is about to collapse on them!

As far as fighting enemies who are already in a building, you'll want to use "house to house fighting" tactics. You definitely shouldn't just stand in the street out front, firing in! Without cover, you'll be cut down in short order. You shouldn't expect mere rifle fire to flush out the guys who are hiding inside, either. You will never want to order your men to rush an enemy building without a plan, or to blast a building to rubble before considering whether you'll need to use that building yourself later.

Instead, to take buildings, you'll want to coordinate an assault. As we've seen from our testing here at Relic, a good combination is a machine gun to pin down the enemy, then an assault squad to lob in a few grenades. You'll be able to suppress and flank, then move in for the kill. You'll want to use snipers as well, since their pinpoint accuracy allows them to pull off headshots against enemy soldiers who stand near windows. Sometimes, the only counter for an enemy sniper is your own sniper! But when all else fails, you may find yourself using this motto: "go heavy, or go home." You'll be able to call in mortars, bazookas, tanks, antitank guns, Panzerfausts, anything with explosive rounds--which will work wonders on that temporary fortress. Satchel charges (a specialty of airborne troops) or demolition charges from your engineers or pioneers will also help, as will flamethrowers to roast any entrenched soldiers who wander too close to the doors.