I have worked on three cover shooters now and I play an awful lot of them (I am currently wearing a Gears of War sweatshirt). The reason that my family finds me hard work and I have never once introduced myself to a real girl in the meet-space is that one of the things I find most exciting to talk about are the esoteric aspects of cover placement in levels. I am not someone who enjoys logic puzzles but I do enjoy puzzle like environments where the puzzle can be solved in multiple ways and I can express myself. This is the essence of a battlefield in a cover shooter (I realise this holds true for most action games but I am referring to cover shooters specifically).
One of the reasons we find videogames fun is that we enjoy making decisions. Humans enjoy decision making and we do it all the time. The times we don’t like making decisions are the times that we are mentally ill equipped to see the different outcomes of one or more decisions or know the outcomes and do not relish them. Videogames provide playgrounds for us to make decisions and experience the outcomes. More and more games are asking us to make more absolute decisions. I recently played Dragon Age: Origins and I had to make genuinely tough decisions at various points in the story. I didn’t know what the outcomes of these would be (in real world we can make better judgements but in a game deciding to side with the werewolves rather than the elves could very well result in your character turning into a break dancing elephant covered in maple syrup for all you know) and the impacts of those decisions emotionally gut punched me.

Cover shooters present the player with a fairly limited set of combat verbs and over the course of the opening hours of the game we test the limits of those verbs and the affordance of the game mechanics until we build up a clear mental picture of what we can and can’t do and also what the enemies can and can’t do. This allows us to amass a great deal of knowledge about the game and then use this knowledge to solve the puzzle of the next combat arena. Over the course of the game the puzzles grow in complexity (angled cover, verticality, enemies burrowing up from the ground etc.) and we keep adding to our knowledge about what is possible in the game as we grow our mental framework of all the different interactions available. The number and difficulty of decisions grows and grows and we keep making these decisions with a high degree of success. There is always the chance of catastrophe but as we grow in confidence we tend to mitigate and make better decisions. When we do fail and make the wrong decision the results are often gob-smackingly hilarious if the game is fair or screamingly frustrating if the game is unfair (a SPAS wielding enemy in R6V spawns behind you for example).
So what decisions are we talking about? When games are discussed the word decision usually means a good or bad choice you make in the story. Do you side with the Jedis or the Sith? Do you sleep with the bi-curious elf or the goth slut voiced by Chloe from Uncharted 2? Army of Two has these choices but in this case the decisions I am referring to are the minute to minute decisions we make when we have our thumbs on the sticks and fingers on the triggers.
Example cover shooter decisions:
· Do I slide to this piece of cover and get separated from my team mate who can revive and cover me?
· Do I use my last grenade in the hope of flushing out the enemy on the mounted gun?
· Do I hit reload now or when my clip runs dry and I have a longer reload anim?
· Do I crouch and keep low or do I utilise my speed of running to get to cover?
· Do I go to the cover on the left or the right of the door?
· How pale is that grenade indicator? Can I survive the blast and keep this preferential piece of cover or do I have to expose myself to get out of damage range?
The list goes on and on.
These are all incredibly important decisions and go some way to create that ‘fun’ thing people keep talking about. Army of Two: The 40th Day’s combat area design is pretty excellent all the way through (a couple of annoying spawn points towards the end irritate but otherwise it is generally good) and does a great job of building up the player’s mental model of the game and allows them to make complex and rewarding decisions throughout a fire fight.
What sets Army of Two: The 40th Day’s apart from other cover shooters is the width of each combat area. If we examine a typical Gears of War combat arena we see that it is generally rectangular and you can see nearly all of the area from the entrance. Once you enter the arena enemies spawn at one end and advance towards you and are engineered in such a way as to allow you to advance on them and thus place your chainsaw in every major organ in their body. When you play Gears 2 (assuming you have played the first and have experience of their level design) and look at an arena you can quite quickly understand it, make decisions about it and mentally play out the overall flow of combat during your time in there. This is not always the case and nor is it a bad thing. In Gears you get a second to look at what is happening and then you dive in, chainsaw revving.
In Army of Two (I'm already sick of writing The 40th Day so assume I am referring to the latest one and not the first one) the arenas are often not entirely visible. Sometimes 50% of an arena is hidden from view at the entrance, sometimes more, sometimes less. When you enter an arena enemies are already active as well. While more will spawn during the engagement, some are already in the arena. AoT features a couple of interesting pre-battle mechanics; mock surrender and hostage taking.

You will sometimes come across groups of enemies that are round a corner and can’t see you. When you walk round the corner they will become alert and you have a second or so to mock surrender. This makes your character raise their hands as if surrendering and the enemies will hold fire and approach you. This then allows your partner to flank them and fire on them while they are off guard. Or perhaps you both mock surrender and as the enemies approach, confident in their victory, you enter a slow mo quick draw and quickly take them out while their weapons are lowered? This is never compulsory and you could mow them down from cover but it allows you to make a more complex decision about the fire fight.

Some enemies will have their back to you when you encounter them. If this is the case you can sneak up and grab one as a hostage. If he is a leader the other enemies will lay down their weapons and you can either tie them down or execute them. If he isn’t a leader they will open fire on you, killing their own man but crucially buying you a few seconds of immunity as their bullets hit him.
So there we see two layers of choices added to an otherwise ordinary fire fight. It doesn’t stop there however.
Back to our combat arena that is 50% obscured. We have entered the arena by mock surrender and through either or team mate sniping or through a quick draw we have eliminated a group of guards (crucially, by not rushing them and catching them off guard we managed to stop them from locking down a weapon crate and we have secured ourselves an awesome new shield for our shotgun) and entered the fight proper. Enemies that were active in the distance are alerted to us and are closing in, more enemies are spawning now we start making a huge number of important decisions in very rapid succession.
We don’t know where every enemy is in this arena as we need to explore it to make a mental map of the structures and cover positions within the arena. Or do we sit back and wait for them to come to us as we are hesitant and unsure? Do we stick together and flank right to explore the deserted animal cages in this zoo in order to use the low walls for cover and take control of the flank? Do we fan out into the centre where enemies cluster around the dreaded red barrels (scourge of henchmen everywhere)? By doing either of these have we left the left flank exposed and is someone working their way towards us? Should we have stuck together? Should I use my grenade to save my partner who is being flanked or save it in case I need it? Should I retreat and work my way up one of the flanks to cut off the advancing squad which may not even be there? Can my partner hold it down while vault over this wall to collect the stash of money? Am I in a safe position or am I sat near a spawn point? What’s on the other side of this wall? Maybe if I boost my buddy over it we can pincer movement that turret that is pinning us down?

Army of Two has more combat verbs than the game that inspired it and this leads to dramatically more exciting fire fights. Gears is exciting and brilliant and the second one has some great set pieces and variety but ultimately most of the standard fire fights play out the same. Where Army of Two succeeds and evolves the formula is that the combat puzzles are not solved as soon as you enter the arena. The puzzle can be solved in multiple ways with your own expression and the puzzle evolves as you play it and explore. The second to second decisions you make have impact and meaning and are exciting to replay and experiment with.
Army of Two is getting mediocre to good reviews and this is because its brilliance is hidden behind an awful story, disconnect bugs, shortness and the feeling of marketing driven design choices. It is quietly evolving the cover shooter genre though (you can spin emplaced enemy turrets around!) and designers can take away a number of lessons from the design and layout of the combat arenas and the options the player has within them. I love me some decision making and AoT has it by the truckload.
Pictures from:
http://ps3thevolution.com
www.eurogamer.net
www.kotaku.com
www.ea.com