DOOM Game/Level Flow Analysis

Been playing around in the DOOM SnapMap editor lately.  You can check out my first map in an older blog post here.  Moving forward on a future map though, I wanted to create something that would match the quality of levels from DOOM’s campaign.  As if I was on the team at Id Software and asked to create something to fit snugly into the campaign.  The following exercise is a great way to get acquainted with another designer’s work and is phenomenal at giving perspective on the higher level design choices that make up an experience.


The Exercise

There is nothing overly complicated or fancy about creating a game flowchart.  It is essentially a visual representation of the player’s actions during a particular amount of time.  For this chart, I found a competent playthrough of the level and went frame by frame, recording the players actions.  Once complete, I had a large spreadsheet of raw data that only needed to be organized into useful visuals for analysis.

Break Down

General Flow


First and foremost, a general (perhaps slightly complicated looking) overview is useful for spotting out any early patterns.  Here you can see when and what the player is doing along with any items they may pick up along the way.

Observation #1 – Sections Heavily Separated

Combat seems to be kept in clumps instead of sprinkled in throughout the level.  There are clear and distinct moments for combat and very separate moments for exploration.

Observation #2 – Interactables/Mini-Objectives

For the most part, large exploration areas are consistently filled with interactables and pickups.  The player always has something to do or an object to get to.  Think of these as short term objectives that link together to pull the player along.  A clever way to motivate players, often directing them down the critical path without the use of a compass marker.

Observation #3 – When It’s Combat Time, It’s COMBAT Time

When the player enters into combat, it is strictly time for combat.  There are rarely any interactables or pickups apart from ammo and power-ups present to distract the player.  Fairly static environments further support the focus on enemies.

Action Ratios


This section consists of a pie chart of all actions performed as well as several percentage comparisons that I found insightful. This may all appear to be just random data, but it serves to give perspective on the overall design goals.

Observation #1 – Combat Is King

This is probably obvious, but combat is the most important aspect of DOOM.  The player will be spending a majority of their time in uninterrupted combat sequences that take up the bulk of a level.

Observation #2 – Gameplay is King

Roughly 83% of the player’s time was spent “playing” the game, leaving only 17% for cinematics and various other control restricting actions such as opening a door or even loading. In a day where a lot of AAA games push that film-like experience with long cutscenes and detailed exposition, DOOM utterly refuses to take control away from the player.

Observation #3 – Narrative is NOT King

To further the point above, only 15% of the player’s time was spent in narrative enriching moments.  Only 29% of that 15% (ok… now I am just getting carried away with percentages…) is spent in control restricted cinematics. Point is – set the player up with an objective and just let them at it.

Combat and Intensity Arc


This is where things get exciting.  For the above timeline, all actions performed during Exploration were merged under the umbrella of Exploration, the same done for Combat.  The end result is a cleaner visual along with an understanding that there is nearly as much non-combat related activities to perform as combat.  I then ranked each encounter to create an intensity arc to visualize the evolution of the level.

How I Ranked Encounters


I used a simple rating system to determine how intense each encounter is.  I started by assigning the weakest enemy, the Possessed, a value of 1.  I then proceeded to assign higher intensity values to various demons when compared to the Possessed.  Once finished, adding up the values of all demons in an encounter led to an intensity rating.  A fairly subjective process, and by no means a perfect science, but a pattern does begin to form.

Additionally, due to the horde like nature of the Imp demon, for every three that spawn, I raised the encounter’s intensity rating by 3.  The intensity of an encounter is merely a feeling and having several Imps clawing at you definitely puts the pressure on.

Observation #1 – 5 Combat Sections


There appear to be 4 major combat sections prior to the 5th section’s boss fight.  Each with a distinct beginning and end.  These would be the main level loops, mini-sessions that provide a sense of accomplishment several times throughout the entire level.  It would be after the finale of a section that a check point be presented, allowing the player a decent point to put the game down for a moment or to continue on.

Observation #2 – Rest

The more intense the fight, the longer the exploration/rest period after.  This holds particularly true for Section 1,2, 3,  and 4.  Section 5, the boss fight, is a bit special as it has a long dialogue section in an elevator to give the player a moment to breath.  These rest cycles give the player a moment to calm down and evaluate their surroundings.  To make any adjustments to equipment and prepare for the next combat section.

Observation #3 – Combat Intensity Arc


By placing the encounters on a line chart, we can easily see the roller coaster of intensity through each section.  The designer was smart here.  Each section has a variety of intensity levels to keep the experience interesting, usually ramping up to the most intense part near the end. Each section’s finale then slightly more intense than the last.  The major outlier being section 3, as it starts off at it’s most intense only to trail off.  Remember, there was a long exploration section prior to Section 3 in which the player had plenty of time to rest.  Additionally, one shouldn’t be afraid to flip the formula around to shake things up for the player.

Bonus – Why Have a Roller Coaster of a Flow?


Ok,  Perhaps not the most elegant title, but it does make for a pretty good analogy.  First – You may think the intensity flow should look more like a straight line, always growing in intensity and difficulty.  The thought being that it gets more fun the more intense it gets and the player is eased into the difficulty.  It’s not a bad thought honestly, but imagine a roller coaster that only went up (for 30 minutes) only to fall once at the end.  Some people would become incredibly stressed as the anticipation built, others might just become bored as nothing is really grabbing their attention.  I’d imagine in general, most wouldn’t enjoy the ride.

Now picture your favorite roller coaster, full of dives and climbs.  Various heights to keep you on your toes with the final drop the great finale of the ride.  Now imagine your game flow in such a manner. The drops in intensity give players a moment of superiority, while the quick ramps up put them back on their toes, creating a rhythm to the experience without exhausting them, thus creating a sense of flow and immersion in the player as they eagerly continue through the level.


It’s important to keep the overall flow of a level in mind when designing, how each encounter connects to the next and how the experience feels as a whole. The above analysis was on DOOM, but many of the observations here can be applied to various other action related games.  Now, with the flow of a level charted out, creating a new level to feel consistent should be that much easier.

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