AZ are not limited to one encounter, several can occur within that space. Areas designated for fighting are Combat Zones (CZs). CZs may or may not be defined by physical boundaries – it could be a courtyard, it could be an open field. Players should be able to easily recognize a CZ by identifying core gameplay elements like: a goal, an exit, cover, chokepoints, secondary routes, and of course enemies!
Every battle can be broken down into its tactical elements:
- Recognize Opposition – Find the bad guys!
- Recognize Environment Variables – Where’s the cover? Where’s the Kill Zone?
- Plan the Attack
- Attack Opposition – Kill!
What’ makes a great CZ? The layout! It defines where the player will be looking, moving, shooting, taking cover, and being shot from. The first step is to create a 3D draft of the area and placement of all key objects that will define the CZ.
By no means should this be the final version! The 3D draft should be far along enough to convey the uniqueness of the layout, however.
Most battlefields fall into one of the following three shapes:
- Corridor – hallway or street
- Field – rooftop or room
- Bottleneck – features a tapered region (for example a hourglass chokepoint).
The World Isn’t Flat!
Most common, and easiest to produce are flat layouts with random pieces of cover. Possibly okay as an early training level, with little to no need for free-looking. Through the course of the game, that gets boring – “been there, done that.” To avoid these doldrums, fully exploit the fact that the world is 3D by creating layouts that offer a variety of paths, cover locations, and firing positions for the player to take advantage of. One key to remember is that “above” and “below” are great places to direct the player’s attention with new threats and opportunities.
Give the Player Choices
Let a player decide if he wants to open fire and go in guns blazing, or use stealth and sneak up on enemies ahead and prevent them from knowing he’s around.
Different play styles are supported by Action Shooters: run & gun, pop & shoot, or sneak & kill. When designing your CZ layout, accommodate these different play styles to ensuring not only that the player has options, but that different players can use their preferred style of play. Is there way to circle the enemy undetected? Does the player have a variety of cover options? Can the player exploit something in the level to “trick” the AI into behaving a certain way? This can be something as simple as luring enemies into a chokepoint or as complex as creating a distraction that draws enemies away from where the player wants to go.
Is it Obvious?
Giving the player multiple choices and paths within a CZ add lots of replay value. But, all is for naught if the player can’t see it. Avoid trying to hide alternate routes and options.
Risk and Reward
There’s nothing wrong with letting the player feel empowered and godly, even if it is for a short period of time. The hunted becoming the hunter can be very compelling (Pac-Man eating the power pellet). Within the layout, consider the placement of objects or items that will give the player a huge advantage in the battle. For example; a powerful weapon prominently displayed in the middle of the battlefield – the player can choose to play it safe by staying in cover while continuing to fight it out, or try risking his life and dive for that weapon.
By using similar looking cover objects throughout a level, the player starts to see the game mechanic and loses immersion. The player can recognize an upcoming battle. As the player gets close to an area with a bunch of similar objects placed in a way that suggests a “dash & cover” path, the element of surprise is lost. Try to use a variety of different objects to provide cover, and consider whether it looks natural or not. For example, why not use the corpse of a fallen creature or vehicle for cover?
Ideally, the game engine supports dynamic cover. There are two aspects to dynamic cover: reducing it or building it. Cover is reduced by allowing cover objects to take damage. As the object takes damage, cover is degraded, perhaps eliminated. Cover can be built up by allowing cover objects to be moved or constructed during gameplay. A simple example is to move an armored vehicle in such a way that the player can take cover behind it. A more complex method that depends on deformable terrain is to treat craters caused by explosions as cover.
Why is the cover there? Let’s answer this from the ground up:
- Is the terrain smooth, rolling, jagged, or drop-offs?
- Is there a stream, river, or dried-up creek bed?
- Is the vegetation sparse or dense?
- Have buildings or trees been knocked down?
- How do people get in and out of the area?
- Is it old or new?
- Is the cover man-made? Why are they here?
To re-enforce the suspension of disbelief, the layout needs to be believable. This isn’t to say that structures in the real world always make perfect sense, but when you encounter something goofy in the real world you accept its existence and shrug it off as weird. In a game however, players perceive this as laziness on the Level Designer’s part and it impacts their suspension of disbelief.
There are a few things to keep in mind that help preserve their immersion:
Functionality – The layout must appear to be functional. The exception is only when oddly placed objects are needed for an effective CZ. For example, if it’s a warehouse, then how do items get loaded and unloaded? Can everything fit through the doorways? Lots of games feature tons of crates scattered mindlessly through areas that wouldn’t logically have crates in it… why?
History – How long has this area existed? If it is old, does the layout reflect this? Is it broken or in disarray? Thinking through the history of the layout helps to generate ideas about the structures and their state. If it’s an old area, could you just walk in through the front door? Is it overgrown? Is it decayed? Maybe another way in through a collapsed part of a perimeter wall would fit better with the age of the layout.
Characters with purpose – Nothing breaks the illusion more than enemies that are patrolling predictable loops or just standing and idling, waiting to be killed. What is their role? What should they be doing when you enter the area? If they just arrived are they setting up base and unloading? If they have been there for a while, what do they do to waste time?
Justifying it creates a believable environment that simply isn’t a random assembly of objects strictly serving the purpose of creating a memorable CZ.
Stacked Combat Zones
Be careful of having several CZ active at one time. By putting more than one CZ on the back burner, it risks “Fire Hosing” and diluting the player’s experience or confusing the direction the player should be advancing.
Combat Zone Companions
Several elements help create an effective battle…
- Kill Zone – crossing the critical threshold for life and death.
- Defense Zone – at the edge of the Kill Zone to help decide how to deal with it.
- Safe Zone – not always present, these can offer short ways to bypass conflict.
- Strategic Points – places that can tip the scale to victory.
- Attack Direction – from a tight, focused direction all the way to being completely surrounded.
A Kill Zone is defined as an area in which the player or AI is without cover, under fire, and likely to be killed. This area can be visible (landmines on the ground) or virtual (tracer fire). The effectiveness of the Kill Zone determines difficulty of the firefight. Without an effective Kill Zone, the player doesn’t need cover and eliminates one of the key ingredients intended for gameplay.
Make it Challenging!
As the player gets used to the concept of a Kill Zone, gameplay runs the risk of becoming stale if CZs begin to feel predictable and static. This is especially true if the player is simply performing a “pop & shoot” from the same Defense Zone throughout the battle. Designing Kill Zones that change angles and positions force the player to find a new Defense Zone. This helps create the impression of a dynamic world and the illusion of intelligent AI.
Ways to achieve challenging Kill Zones:
- AI flanking the player’s Defense Zone
- AI fallback or charge – depending if the player is whittling their numbers down, or if there has been a standoff.
- Destruction changes in the zone
- …Buildings or trees fall and change the layout
- …Destroying a bridge, causing enemies to fall
- …Walls can be knocked down, or have large holes made in them
Make it Effective!
Based on past experience, some issues with creating an effective Kill Zone exist:
- The player has no true Defense Zone
- …AI behaviors allow them to attack the Defense Zone without any care for their survival.
- …When destructible cover used as the only Defense Zone cover
- …When attacks bypass the use of cover; such as explosive splash damage.
- The player cannot recognize the Kill Zone. Without this, the Defense Zone is also unknown.
- The player cannot see alternate paths or gameplay options.
- …If it’s hard to find as a designer, it’s invisible to a player.
- The Kill Zone extends beyond the intended area.
- …Due to AI sight distances, they continue to fight well past the Defense Zone
- …AI should fall back when the player reaches a certain distance from the battle
- Every battle isn’t necessarily the FINAL battle. Be willing to throw the player some “gimme” battles within the level as part of pacing and letting the player feel powerful
The player is likely to backtrack from a Kill Zone they perceive as too tough and resort to long distance sniper tactics to whittle down the opposition. The result is a drastic reduction in pacing and intensity. The player gets the impression that the game is impossibly difficult unless they play super cautiously… and the player loses interest.
The required companion to a Kill Zone is the Defense Zone. It’s an area in which the player or AI is safe behind cover. Without it, the game boils down to shoot or be shot. This requires several cover options for the player to use – preferably of different shapes and sizes and strength (whether it is permanent or degradable.)
A Safe Zone can provide a couple options:
- Regroup Point – a place to give the player time to think about how to proceed.
- Secret Flanking – a way for the player to flank the enemy’s Defense Zone undetected and sneaking through parts (or all) of the Kill Zone.
Within any of any of these sub-zones (Kill Zone, Defense Zone, or Safe Zone) there might be locations that give someone the upper hand. These are Strategic Points. For example, the crest of a hill in the Kill Zone is too soft to provide any cover, but it does provide height above the masses. A Defense Zone might have a murder hole facing the main gate acting as a Strategic Point (a Kill Zone chokepoint).
Freeform vs. Defined
There are two main types of CZs:
- Defined – explicit chokepoints in which the player has to cross and overcome a Kill Zone.
- Freeform – a loose, exploration based CZ in which the Kill Zone isn’t strictly enforced and could come together at various areas within the CZ.
A level that contains a balance between the two types helps prevent player fatigue. Defined CZs are usually more demanding of the player’s skills. From an overall difficulty curve throughout the course of an entire game, later levels could feature more defined CZs than freeform CZs.
It should be noted that a freeform area with plenty of enemies could end up surrounding the player making for an impossibly difficult situation.
Switching it up
Is it possible to design a CZ that begins as freeform and then becomes defined or vice versa? The switch could be an exciting component and make for a “memorable moment”.
Consider ways to increase a CZ’s difficulty when creating them. Some obvious ways involve enemy numbers and placement. Another way would be the location of inventory and weapons. More creative options could affect the actual geometry like changing cover to create a smaller Defense Zone or larger Kill Zone!
From a tight, focused direction all the way to being completely surrounded. (Details coming soon).
By understanding the ingredients to an encounter, it becomes easier to prepare a great event. What will players remember that makes this event different from the last one?
Top concepts to remember when designing on a new location:
- The layout
- Key structures
- Cover objects
- Multiple choices
- Effective Kill Zones
- Safe Zones
To create tension, a level must press a conflict between safety and danger. If there’s no downtime, it’s hard for there to be an up. The game must establish anticipation with consistent threat cues. For example, Resident Evil meticulously defined corridors at the beginning of the game as safe zones – only to send a zombie dog crashing through a window a short while into the game, breaking the sense of security the player has built up and giving a sense that nowhere was absolutely safe. Be on the look out for write up “Designing Fear” !
For more details on making great levels, read PART 2: Design Structure.