The Eighty Twenty Rule

1st August 2011

Single Player First Person Shooter Maps and Mods for Half-Life 1, 2 and Episodes 1, 2 and 3

I’ve mentioned this before in some of my podcasts and even some reviews but yesterday during the 100 SDoN Podcast 03 it came up again but in a slightly different context.

Let me start at the beginning.

I have a theory that a good Portal/Portal 2 puzzle should follow the Pareto Principle (also know as the 80/20 rule) in that it should take me eighty percent of the time to workout HOW to beat a chamber or puzzle and twenty percent of the time actually DOING it.

Let’s follow the process in a little more detail….

  • You enter a chamber.
  • It’s quite possible the exit can be seen with a few seconds.
  • Most of your time is spent working out the exact route and actions required to get there.
  • You may perform a few failed attempts, perhaps choosing the wrong area to place a portal.
  • Eventually, you get it right and you reach the exit. (well done, by the way!)

Now, if you were to replay that chamber, you already know HOW to get to the exit and you do it within a few moments, probably less than a minute.
So, unless you are looking for new ways to beat that chamber, it’s over in no time.

To take a quick aside. Portal and Portal 2 probably have the least amount of actual “playing” time than any other AAA retail game released in the last few years. Think about it. You spent more time going up and down those damn elevators than shooting portals!

Of course, it is only a rule of thumb and there are probably great chambers that don’t follow it. But as a general principle I think it works quite well. I don’t like to spend too long making difficult jumps or any other fast-reaction movement. I play portal for the puzzle element, not the skill element.

Can you image playing chess where once you decided on your move you had to do some sort of acrobatic movement to place the piece? Oh, and not just that but all with less than a second! You get my point.

Yes, some chambers are fun because they require some precise movement, but only for a limited number of players. That’s why the actual retail games don’t have this idea as part of the core gameplay – that is for the hardcore players and this rule of thumb doesn’t apply.

Now, yesterday, I extended my rule to normal FPS games and mods, but flipped the percentages around.

Let’s think of it like this….

  • You enter an area and the way is not obvious. (In this case, I am thinking of the equivalent of a Portal chamber, not just a simple room or corridor.)
  • You do some quick exploring but are attacked by enemies.
  • You now know exactly where you need to get to.
  • The next 5 minutes are spent trying to get past those enemies.
  • Much more time is spent getting somewhere than actually working out where to go.

In the case of normal FPS games, there are probably a lot more exceptions than in Portal chambers, but for larger areas, especially indoors with multiple levels this rule of thumb might work quite well.

That’s why I don’t mind games, maps or mods that are quit linear. It’s the shooting and skilled based actions that are most fun in these games, whereas in Portal chambers it’s the puzzle aspects that is most rewarding.

What do you think? Is this rule just too vague?


  1. Fights could lack variety, that’s true, but the FPS course still almost always will be linear, and even level design will be centered around this ‘line” because otherwise your player will stuck in thoughts: “What I suppose to do now?”. You could even track this ‘line” in so-called open games, because even them force you to go somewhere and complete some tasks. Variety in them created through rich environment. And then you’re bored or already completed that kind of game and playing in “free mode” (take modded STALKER or GTA IV as examples) you’ll make tasks for yourself, like “Get six stars and escape through subway’.
    Also a well planned shootout in “classical FPS” could be a puzzle itself. With questions: “Who gonna be my first target?”, “Where I can get supplies?”, “How can something in environment help me?”. And the scenes with most variable solutions brings us most memorable pieces of gameplay. The only difference with Portal puzzles is almost absent delay between ‘see” and ‘do” but FPS is mostly for your spinal cord and Portal is mostly for your logic so you should be OK with this my friends! Let’s say you spice up FPS with ‘think” moments amd also spice up Portal with ‘react” moments.
    So I think “80% see/20% do” principle is perfect for Portal chambers. (That’s why I hate Portal: Prelude btw, because it’s mostly based on reflexes, unnatural reflexes if you ask me 😀 )

  2. Hec

    I actually agree, many theoretical explanations actually describe reallity well in many cases and gaming design is not an exception, but I also think we as gamers are more complex than just theoric models, I mean it’s great and convenient having the 80/20 rule I think of that as a satisfaction rule almost in many aspect of life that it supposed to be highly enjoyable as a really great juicy steak ready to be tasted, u spent 80% of the time with that great flavour in your mouth and delighting it but actually the steak is all eaten in a 20% of the time, there’s when u stop and remember that moment that has alredy happened as a really great meal, but maybe the person wants more!!, at least I think of me as that kind of person or gamer, I allways want more, on the other hand mods just based on puzzles are some thimes overwhelming to me!, they most of the time broke the 80/20 rule and the most annoying ones are the ones which make me do like 80/100, that’s it a not clear path or explanation, and soo much job to do in there!!!, even there the logical skills are an important value and not many gamers are at the same level!, I have memories of portal prelude maybe the most annoying portal mod, really and I mean really screwed up by the fact that developer’s assume gamers, are super portal and all powerfull skiled players!!!! god what a way to screw up a mod, but I don’t know im more a passional gamer than a liogical methodic one, and I love to enjoy the gametime, and when all it’s over if it was a great mod or game, sorry but I think I allways want more, at least with HL and Call of dutty series that has happened…

  3. Hec, I like how you compare the length of HL to the Call of Duty series, even if you didn’t mean to XD
    The 80/20 rule does work, however it is a bit vague as the percentages can be tweaked for each mod/map. Although I think the 80/20 ratio is a good starting point.

    I think in a fps, you could also have 80% fighting or getting past a puzzle and 20% exploring and resting from a fight/puzzle. With percentages it is dynamic as it varies depending on the size/length of the battle. For example, if a large battle lasts 16 minutes then the player should be able to walk for about 4 minutes to catch their breath. If a battle lasts 4 minutes, they should be able to walk without action or a puzzle for 1 minute. Although this is a very general rule, mappers should experiment more. What I mean by 1 minute without action, is, the player can walk the fastest route for 1 minute before stumbling upon a “puzzle” or hostile’s. This means a good mapper can expand the environment a little, adding treats such as ammo and even secret weapons, allowing a curious player to explore, spending much more than 1 minute. Otherwise it could feel like battles are too often and the percentage should be something like 70/30.

    This may work with puzzles too as if someone is trapped in an area for 24 minutes until they finally finish the puzzle, they would probably not want to solve another one straight away, although a little action may be a defibrillator.

    What do you think?

  4. Aazell

    I think youve missed one element here.
    Some obstructions take skill to get past and some puzzles take skill to solve. Skill with the game controls I mean. So a great puzzle takes time to work out what you have to do then takes skilled controls with the game to get past.

    So there is some replay value to be had.

    Grav gun puzzles are fantastic for this.

    1. I did say it was only a guide. Not every situation should conform to it.

  5. I think your 80/20 rule is good, but it should be noted that it works both ways: Puzzles that are hard to figure out should be easy to execute, and puzzles that are easy to understand should be hard to execute. when you have easy to figure out puzzles with solutions that are easy to execute, it doesn’t even register as a puzzle, but when you have a hard to understand puzzle that is also hard to execute, then it becomes frustrating, as you can’t tell if you are doing the puzzle wrong, or if your skill simply isn’t high enough to preform the required task for completion.

Leave a Reply

Comment Formatting Guide

Well formatted comments are much easier to read. Please copy and paste the HTML Tags to use in your comment

  • HEADER: <div class="fix"></div><div class="sbe3">TEXT HERE</div>
  • BOLD: <strong>TEXT HERE</strong>
  • ITALIC: <em>TEXT HERE</em>
  • SPOILER: <span class="spoiler">TEXT HERE</span>