Judge A Map By Its Cover

Cover objects are a core piece of a level designer’s toolbox, and there are many ways to use them. The examples below look at de_dust2 from Counter-Strike: Global Offensive, but some of the same concepts apply in other first-person shooter level design.

For those unfamiliar with the basics of Counter-Strike, the defusal game mode pits a team of attackers (Ts) against a team of defenders (CTs) in a series of 1-life rounds. The attackers win a round by planting and detonating a bomb at one of the two bombsites, or by eliminating the defenders. The defenders win a round by eliminating the attackers, defusing the bomb, or by running the clock out.

A full round of Counter-Strike tends to have a few phases of play:

  1. Attackers probe the enemy defenses for information and opportunities to gain map control.
  2. Attackers commit to taking one of the bombsites, spending utility (smoke grenades, flashbangs, and molotovs) to gain an advantage in the fight.
  3. If the attackers succeed in planting the bomb, defenders now have an opportunity to attempt retaking the bombsite against the attackers. This behaves as a kind of role-swap where attackers are now defending and defenders are now attacking.

Cover plays many roles in each of these phases.

Also for context, this article isn’t about competitive Counter-Strike map theory and tactics. My interest is as a level designer and my experience with de_dust2 is as a casual player where some of these patterns play differently from how they play in the esport scene.

Freestanding Cover

Freestanding cover objects provide a full loop of pathing around them. Players can use these cover objects to hide or hold against many angles. Here on B site for example, a player can use the tall box to hide from upper tunnels (left of image center), or to hide from window and defender arch (off screen to left)

Each line here is an angle this tall cover can block. Pink is to defender doors. Red is to window. Blue is to upper tunnel.

Freestanding cover leaves options open. A player can choose to peek from either side, loop around it, or disengage. They can choose to hold close to the cover and try to peek wide and fast, throwing their opponent’s aim, or they can try to back off and play from range. So long as they are in an even fight, they have options to play that cover to their advantage. Even in a 1v2, freestanding cover can help the outnumbered player juke and stay alive, burning precious seconds off the clock.

Because of this versatility, freestanding cover tends to work best on objective sites where players may duel or attempt to run the clock down.

Directional or Team-Favored Cover

On de_dust2’s B site, there is a cubby in the wall where a large wooden gate is shut. This recess is deep enough for a player to hide behind the post and use it as cover against an attack from the upper tunnels.

The team-favored quality of cover depends on how each team approaches it. For the defending CTs, this cubby is fully visible; they don’t need to clear those angles when they enter the site. But for the attacking Ts, this cubby could hold a sneaky player, and they could lose the round if they don’t clear that angle.

How the cubby looks to a defender holding against upper tunnel
How the cubby looks to the attacker attempting to push into B site

Even once the attacker has cleared the cubby, they can’t use this same cover against the defenders. The cover offered by this cubby is only useful against upper tunnels. Even worse, the cubby is exposed from the defender archway, which means attackers can’t use this cover when they are holding the B site against a defender retake.

Red lines mark the angles from which the cubby is exposed

Although this cubby is defender-favored, it still requires a big commitment. If attackers throw a molotov into the cubby, that defender has no good options. Unlike the freestanding cover on the site, the cubby doesn’t allow a defender to disengage without being spotted.

The cubby is also small enough that a long rifle muzzle can stick out. The defender in this cubby either needs a short-barreled weapon or to play anti-flash (looking at the wall) and wait for a teammate to provide info. A deeper corner, which could hold more defenders or give a single defender more options, would significantly shift the balance of this site.

Another Team-Favored Cover

On the attacker approach to A site, there is a large blue garbage bin. This is a massive cover object creating a deep pocket of cover on either side. However, the attacker entryway to this area minimizes the cover that the blue bin could provide to a defender.

Attacker approach to long A, blue bin in center. Red lines mark the angles that attackers need to worry about.

A defender could try to tuck into the corner on their side of blue bin, but their weapon muzzle may stick out, and the shallow depth of their corner favors the attacker clearing that angle. (By having a wider sweep of the corner, an attacker would see the defender’s shoulder before the defender could see the attacker’s.)

The defender perspective onto the attacker entrance at long A and the blue bin. Red marks the main attacker entrance. Pink marks the additional angle defenders have to worry about if attackers successfully take control.

In practice, if attackers successfully make it out the threshold into long A, they can tuck behind blue bin and create a crossfire against any defender attempting to push into attacker territory. By gaining control of blue bin, the attackers can lock the defenders out of this part of the map without a serious expense of utility. If attackers don’t succeed in taking blue bin, they haven’t lost much ground because the defenders can’t use the blue bin against the attackers.

Imagine instead if the blue bin was a freestanding cover object like those crates on the B site objective. If attackers succeeded in pushing into long A, then they would have an additional angle to loop around the blue bins, making it harder for defenders to hold. On the other hand, if the attackers failed to push into long A, then defenders could also take control of the blue bin and use it to hold any further attack against long A. If defenders could use blue bin, they would effectively lock attackers out.


A cover object pivots when players can use the same object against multiple angles. Freestanding cover objects pivot, since they can be played for many different angles, but simple corners can also pivot.

On long A, the timings from the start of a round mean that defenders arrive at this pivot corner just before attackers can push out the arch.

Defender view of long A toward the attacker arch. The pink line marks the pivot. The red line marks where the attackers will appear.
Attacker view peeking long A. The pink line marks the pivot.

This pivot behaves almost like a control point in the battle for map control. Defenders start with tentative control of this angle. If attackers succeed in their push, they can take control of the corner and use this lower part of long A as a staging area to commit to the A-site attack. Defenders could attempt retaking long A from attackers, or attackers could opt to silently disengage and leave defenders worried about an attack that never comes.

Outside of Counter-Strike, payload levels often use corners like checkpoints. Defenders start with control of a corner that lets them hold back the attack. But if attackers manage to push the defenders away from the corner, the attackers can now push up and use that same corner against the defenders into the next stretch of the fight.

Cover can also soften or harden the effect of a pivot. Imagine how some alternatives to long A might play:

Adding a full sized cover object here would create an extra pocket that attackers need to clear on their approach to the A site. To clear this pocket, attackers would be exposed to all of the angles at the top of long A. Also, if a defender has to disengage from a fight on the pivot, they would now have this safe pocket to retreat to instead of being stuck in the killzone of the long A street.

A similar cover object deeper on long A has the opposite effect. This reduces the number of angles that an attacker has to worry about when peeking the corner. It blocks off the sightline at “Goose” (the left corner at the top of the street). This cover also lengthens the distance a defender needs to retreat from the pivot before reaching safety. Attackers could also creep up to the pocket created by this cover and hold there safely, similar to how blue bin functions prior to this area.

The height of the cover also plays a role. If a players have full cover and can still throw utility over the top, this lets players extend their control of the space without stepping into an enemy’s crosshair.

However, for Counter-Strike’s gameplay, any of these cover modifications to long A could upset a delicate balance, making long A plays either the dominant tactic or a nonviable tactic.

A Note About Utility

If you aren’t familiar with the specifics of Counter-Strike, the empty stretch of road on long A may look like bad level design. In Call of Duty, this area would be a death trap, and common Call of Duty layout patterns would suggest the area needs flank routes and more cover here. However, in Counter-Strike these paths are possible in exchange for utility.

Smoke grenades deny vision. Smoking a threshold or t-junction can deny a path or allow a safe crossing. Smoking a corner create pockets of hidden information and off angles for enemies to worry about. Players can also deploy a smoke in the open, like the one pictured above, to create new angles for players to fight around. Smokes behave like cover objects in how they conceal information.

Molotovs and incendiary grenades behave as area denial. They can negate a cover object. In the picture above, my molotov is clearing out the corner behind the car. If an enemy is hiding in the corner, I would hear a hit effect of the molotov damage ticking. The enemy trapped in the corner would either have to deploy a smoke to extinguish the molotov or try to escape the flames and run into my crosshair.

There are also flashbangs, which can blind players or force them to look away for a crucial moment.

This combination of utility makes it possible for attackers to push areas like long A, but it comes at a cost. Each player can only carry so much utility, and grenades cost resources as part of a match’s persistent economy. When players throw their utility to push long A, they have made an investment that requires them to follow through before the smokes fade.

Bigger Patterns

Taken together, these details of cover form a few patterns:

On the attacker side of the map, cover tends to be attacker-favored with opportunities to gain territory and lock defenders out from easily retaking it. I think of this pattern as “footholds”. The attacker side of long A and the upper tunnels are both attacker-favored footholds.

The objective sites are built to support defender retakes, which means they have the most freestanding cover in the map and support a wider variety of engagement angles. There may be some team-favored positions such as the cubby on B site, but these tend to come at the cost of locking a player to their position.

Separating the attacker-favored footholds from the defender sides of the map there are killzones without any cover. For B site, it is the long hall of upper tunnels. For A site, it is the long stretch of road. In both cases, the killzones require a hard commitment where attackers need to spend their limited utility to attempt the crossing.

These patterns reinforce the stages of play I described at the start, and when a map rearranges these patterns, the stages of play change too. Some Counter-Strike maps make the attacker footholds weaker, offering greater possibility for defenders to get aggressive and lock attackers out of options on the map. Other maps make path commitments harder or easier, which affects how defender prioritize positioning and resources. Even within the same game mode rules, a few tweaks to cover can make a huge difference in how a map plays.

Closing Notes

The notes above aren’t comprehensive. Cover has different quirks in every game, even within the same genre. What’s true of Counter-Strike isn’t quite true of Halo or Call of Duty. Despite that, I hope the notes above gave you some new ways to think about cover and how level design can use it.

Thanks for reading,


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s