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Feedback and Loop analysis in Call of Duty Zombies

I analyze the feedback and loop element in the gameplay of Call of Duty Black Ops 2's zombies mode, and highlight some of its successes and failures, and suggest some fixes.

Dustin Treece, Blogger

September 29, 2013

6 Min Read

Feedback/loop Analysis – Call of Duty Black Ops 2: Zombies Mode (Xbox 360 - FPS)


+ Feedback structure rewards players for killing zombies in more skillful or difficult ways (normal zombie rewards 50 points, killing with a headshot rewards 100, and finishing a zombie with a knife rewards 130 points). This encourages the player to continue using more challenging methods of dispatching zombies in order to get more rewards from their actions.

+ When players go down they lose all their perks, which makes it much easier for the player to survive. Losing them is a big disadvantage in later rounds, which results in negative feedback, which makes the player put more emphasis on their own self-preservation because they have substantial things to lose should they go down.

+ If a player should go down, and stay down for a while, they will eventually die, losing all of their guns, perks and items. Plus, if all players go down or die, the game is over. Because players are working together in zombies mode, it is greatly advantageous for the teammates of the downed person to pick them up, as it will give them another gun and anther person to hopefully pick them up if they go down. This negative feedback through dying enforces players to try and enter a positive feedback loop through reviving their downed teammate, and regaining most of their original power as a team.

+ Killing zombies with the different buildable items (tramplesteam, machine gun turret, the swinging blade) doesn’t reward the player with any points. This is a negative feedback system, because is dissuades players from killing zombies this way by not rewarding them with any points like almost every other way of killing zombies does.


+ Players are rewarded for completing each step of the Easter eggs with more elements from the story of the zombies mode.


+ Each map has hidden teddy bears that when the player finds and presses X on them all, they are rewarded with a song.


  • Many times doing when doing Easter eggs in zombies (which essentially involve a list of different tasks and challenges that need to be done in order on each map) there are stalled loops where completing one task or doing something slightly wrong will void the Easter egg and make it’s completion impossible. In the most recent zombies addition, Buried, there is a part of the Easter egg where players must guide a wisp through the map to a certain location to power it with energy. However, players must do this twice, and must use the time bomb device to go back in time to redo this step after it is done the first time. However, if players do not place the time bomb down before they complete the step, they will be unable to travel back before the wisp was used and the Easter egg will not be able to be completed.


  • After the completion of some Easter eggs the players are rewarded with all eight perks that persist, even after the players go down or die. While this is a positive feedback system in itself, it removes the negative feedback from dying or going down, which removes much of the difficulty and challenge from the game.


  • Every time a player hits a zombie with any amount of damage, they receive 10 points. The type of damage does not affect this nor does the amount caused with each hit, just the hit itself. This feedback favors players to use weaker weapons or weapons that have a high rate of fire but low individual bullet damage. This doesn’t really reflect player skill or the difficulty of the hit. Sniping a zombie from far away with a sniper rifle takes a lot more skill to execute on the part of the player than a burst of shots from an SMG up close, but both are rewarded with the same 10 points for each hit, and the SMG has a lot more bullets and can hit much faster than a sniper rifle can, despite its comparative ease of use.



  • Persistent perks are secret or mysterious perks that give the player special advantages in-game. However, how to get these perks and what they do exactly are not ever told to the player directly. This causes a problem with the feedback loop, because the player is getting rewarded, but not fully realizing what he or she is doing to get rewarded, or even exactly what the reward is. The player may be perform an action that is worthy of being rewarded for, but because he or she doesn’t realize that he or she did a reward worthy action, the positive feedback loop is stalled. One example of this that has been largely figured out is the dead shot persistent perk that is given to a player who gets two headshot kills on zombies with one bullet. The perk makes the auto-aim mechanic target the head of zombies, instead of their bodies when using a sniper rifle. However, this is just general speculation and knowledge gathered from other players, not an official rule for what this perk does.



~ Since the game is already rewarding players for more difficult zombie kills with more points, why not add in extra points for killing zombies from far away or for killing them with perks that allow you to do so (PHD Flopper, Buck Cherry, etc.).


~  One of the dominant strategies in zombies is to camp in a single spot, with limited entrances for zombies. There should perhaps be a way to account for this, outside some of the map specific boss zombies like the warden or the electric zombie. Maybe reduce the amount of points players get from kills when staying in the same specific area for multiple waves.


~ Another dominant strategy is to circle zombies around and then get them all into a single line. Most bullets will penetrate through multiple zombies, so players get more points and kill more zombies for each bullet using this strategy. However, what develops out of this is very repetitive play, which isn’t very fun. Incorporating a feedback system that wouldn’t allow the player to earn points on bullets that penetrated through zombies might reduce the amount of points gained from this strategy, and make it less commonly used.


~  Adding in some feedback rewards for more team based efforts might be an interesting idea. Give extra point rewards for assist zombies kills, killing zombies that just caused damage to one of your teammates, or killing the zombies around a downed teammate. This would further reward players that help out their teammates, which can really be a problem in some multiplayer games.


Would Likes/Fixes:

O Fix some of the elements that can make completing the Easter egg impossible, without forcing the players to start a new game.


O Further reward players for more difficult feats, like killing zombies from far away or with weapons that are more difficult to use.


O Reward players with points based on helpful team based actions (instead of just revives).


O Incorporate feedback systems that help reduce the effectiveness of dominate strategies like camping and looping zombies and then shooting them in a line.

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