
The Door Problem of Combat Design - danso
https://gamasutra.com/blogs/AndrewYoder/20190808/348237/The_Door_Problem_of_Combat_Design.php
======
mrob
The fundamental problem is "player benefits from minimizing risk", which is
usually boring. It happens in most genres, e.g. it's especially bad in
roguelikes, where luring enemies to doors is a common tactic.

Of the proposed solutions: cover, hidden information, and enemy leashing are
only obfuscating the low-risk path, not actually removing it. A good player is
still rewarded for boring play, e.g. bouncing grenades at the leashed enemies.

Rewarding risk-taking is a good solution, but hard to implement in a FPS
because there are only so many rewards you can give.

One-way paths are criticized for breaking exploration, but I think it's
possible to get the benefits of them while still allowing exploration.
Consider Ninja Gaiden for the NES. It spawns enemies when you cross certain
thresholds, and crucially it does this every time you cross them, even if you
already defeated the enemies. This punishes retreat by undoing any progress
you made. You're forced to take risks, and it's IMO a better game because of
it.

Some people call Ninja Gaiden unfair, but I think that's because they didn't
understand the mechanic. You could get the same benefits while making it
easier to understand, and more fair feeling, e.g.:

* Clearly mark the spawn triggers

* Visually show the triggers activating, e.g. with particle effects flying from them to the enemy spawn points

* Don't let the enemies harm the player immediately after spawning, so the player has time to react.

* Cap the number of active enemies and the spawn rate from each spawn trigger (Ninja Gaiden has sprite limits, but you can still produce absurd-looking spawn patterns by repeatedly crossing the trigger point).

Ninja Gaiden also has time limits, which are IMO an underrated method of
punishing boring play. Time limits aren't fashionable in modern games, but I
think they should be brought back. They're compatible with exploration by
including hidden bonus time powerups.

~~~
dmoy
> it's especially bad in roguelikes, where luring enemies to doors is a common
> tactic.

Ah ha yes my thoughts exactly while I read the article. I'm not throwing away
an hour of procedurally generated airplane time-wasting fun by walking all the
way into that room, doorway is just fine for me.

The other thought I had was that old America's Army game. When actually played
"correctly" it was extremely slow paced and "boring". It wasn't usually
doorways (honestly doorways were more exciting because you actually had some
suspense about the doors &corners hiding aspect). Rather it was just hiding in
bushes and waiting to move until someone far back told you where the sniper(s)
was looking and if it was safe to bolt to the next bush. For like 20 minutes,
which was an eon considering if you died at the beginning of the round you had
nothing to do, and e.g. CS rounds were like 2 minutes.

~~~
hinkley
I didn't read it but I saw an article the other day about an army sniper
getting a medal for spending 3 days crawling across a field to get a shot at a
high value military target and then another 3 days crawling back out.

Nobody would play that game. (also when did he poop?)

~~~
thaumasiotes
> (also when did he poop?)

Probably before heading out and then once or twice during the week he was out
there. It's not a big problem.

The more urgent question is, how did he get water?

~~~
ethbro
Camelbak?

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teddyh
I liked the original Doom and Doom II back in the day. But it seems that I
played them differently than other people, since both the 2016 Doom, and the
advice given in this article, eliminates my style of game play _entirely_. I
never played much of the 2016 Doom game as a result – it just wasn’t fun for
me. I can certainly accept that it deserved the acclaim it got, since it
allowed the gameplay which other people experienced with the original Doom.
But not my gameplay style.

The article talks about “ _If I want my friend to fight in the arena_ ” and
gives “ _One way path, with the drop down_ ” as one possible solution. I
absolutely abhor arena fights, especially with auto-closing doors or a drop
down. I would always try to trigger as few enemies as possible, and would
always retreat to fight them safely if possible. Why would you design levels
which makes it impossible to play in this style, if some people prefer it? Why
would you design a level to force a specific play style, even though they
might not enjoy it?

~~~
gambiting
>>Why would you design levels which makes it impossible to play in this style,
if some people prefer it? Why would you design a level to force a specific
play style, even though they might not enjoy it?

For the same reason someone designing a sports car will make the suspension
super stiff - because they want to achieve a specific goal with their design.
My grandmother would hate driving such a car as it would be uncomfortable for
her, but it might be an acceptable trade-off for those looking for a specific
type of experience. If you're not enjoying a specific type of game design then
it simply means that the game isn't for you - and there's absolutely nothing
wrong with that.

~~~
tomc1985
What makes the designers intent so sacrosanct? The value of art is in how it
is perceived, not the artists' intent. Often, the two are aren't in sync
anyway

I also enjoy this style of gameplay. Just because it is considered a cop-out
to designers looking to nudge me to be more aggressive or something, doesn't
mean its an illegitimate tactic.

Or is this really about creating gameplay that looks exciting to that accursed
YouTube crowd?

~~~
pawelmurias
The point is to ensure that style of game play isn't more effective. There are
cover shooters that encourage potshots from behind cover that are built to
make that style of play more fun.

~~~
tomc1985
Those sorts of considerations should only come in to play with extreme
examples... it's a very heavy-handed approach to designing gameplay. Unless
you're trying to make an experience very specifically something -- which I
think works only in cinematic situations -- the game should be designed in a
way that accommodates multiple playstyles. A lot of people begrudge heavy-
handed game-design; it ruins player freedom/agency

~~~
gambiting
I disagree quite a lot - look at Doom 2016. It's a masterpiece of a game and
its design does not allow multiple different playstyles. You cannot go and
start sneaking around , the gameplay is extremely focused on always being 100%
balls-to-the-wall, guns blazing and running around like a terminator from hell
that you are. The levels allow different approaches to that style of gameplay,
but fundamentally it cannot change. Does it feel like you have no agency over
its dozen or so levels? No, of course not.

~~~
teddyh
> _look at Doom 2016_ […] _Does it feel like you have no agency over its dozen
> or so levels? No, of course not._

My original comment which brought up Doom 2016 in the first place did in fact
argue that yes, Doom 2016 gave me no choice in how to play. It continually
forced me into arenas where enemies spawned in a circle around me. IIRC, there
were no individual enemies to trigger, only arena triggers. It also forced me
to melee each individual enemy up close in order to gain any health back,
precluding any long-range tactics.

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b_tterc_p
I believe most like playing intelligently. The goal of the level design
shouldn’t be to make the intelligent move less rewarding, but to make the
boring move less intelligent. So I kind of disagree with the offered
solutions. A more modern set of solutions might be threats pursuing from the
rear that make backtracking riskier than pushing forward, mobility or
offensive options that favor aggressive moves over defensive moves, or (and
perhaps I may only dream) non Euclidean level design such that moving
backwards is actually a different area.

Situational awareness in competitive FPS is very impressive. I want to know
what it looks like in non Euclidean space where assumptions about positioning
get an order of magnitude more difficult.

~~~
kemayo
> offensive options that favor aggressive moves over defensive moves

Doom (2016) did this fairly well. It had a "glory kill" system, where getting
very close to an enemy after doing a bit of damage to it would let you finish
it off, and guarantee that it'd drop health for you. It also had a special
melee weapon which would guarantee ammo drops when used. Then it also had
mostly non-hitscan attacks by enemies, so you could dodge most attacks.

This all combined to make a legitimately sensible strategy when low on health
and ammo be running in a zig-zag at enemies, and effectively punished you for
hanging back and trying to hide behind static cover.

~~~
teddyh
Cut scenes are boring in non-story-driven games. So when a game has what
amounts to very repetitive cut scenes, which you yourself are forced to
trigger if you want to get any health, it gets boring and annoying very fast.
Add the fact that _time passes_ during these non-interactive cut scenes, and
other monsters can gang up on you _while the cut scene plays_ , and you have a
very distasteful recipe. It was definitely a large factor in why I never
played much of Doom 2016.

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lubujackson
An interesting flipside of the door problem is what experience is the mapmaker
envisioning? In his first example, why is the default assumption that a player
would WANT to enter a map full of enemies?

Usually this comes from a half-remembered fun of perfectly balanced battles,
surrounded on all sides but managing to wade through them. There is an
interesting parallel to game motivations and fiction plotting: the character
needs motivation to advance into uncomfortable situations, either pushed from
behind or pulled by desire. When you think along those terms, everything else
falls into place naturally.

~~~
hombre_fatal
They're trying to avoid the problem where maximizing combat effectiveness will
minimize fun for the player.

Even if there are players who have optimal fun by door-cheesing every
encounter, you likely want to ensure other play styles are at least as viable
so that players aren't funneled into a one-dimensional tactic. Or that players
aren't forced to make suboptimal plays just to have fun.

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lolc
I've found enemies in shooters to be really weird just idling until you show
up in their vincinity. They should know you're there and be coming for you or
hold defensive positions. Or they could be unaware and unprepared, running for
cover and their guns when they see you.

That was twenty years ago. Reading this article made me wonder whether it's
still the same today. On second though it's probably about offering a game
that allows people to shoot enemies in a satisfactory way. Having enemies too
smart wouldn't allow killing hundreds of them because they'd get you first.

~~~
crooked-v
The current Tomb Raider series does a fairly good job at this, with a mix of
'sandbox' areas with patrolling enemies and 'setpiece' areas where they'll
actively pursue you or you have to assault a prepared defensive location.

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patsplat
In linear single player games lowering the cost of failure is a powerful way
to encourage aggressive play. Games like Super Meatboy don't even make the
player wait after death, encouraging the player to keep trying immediately.

In multiplayer games, looping maps discourage tentative play. Remain in one
space too long and get flanked.

I like the way World of Tanks discourages cautious play with scouting and
artillery

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n3k5
Exploiting choke points to optimise your tactical positioning is a recurring
trope. Some games just expect you to do that anyway. As mrob mentioned [0],
roguelikes are notorious for this; but I wouldn't call that _bad_. It's more a
matter of taste. Particularly in roguelikes, you'll also encounter situations
where the tactical advantage is subverted by enemies that can teleport or
spawn minions behind you.

One common, but somewhat clunky countermeasure is to start the fight only once
you're inside an arena and lock down the exits until the adversaries are
defeated. It's present in many genres, from metroidvanias to ostensibly
tactical action (e.g. the Metal Gear Solid series).

In a Quake-style FPS, having power-ups not just available, but regularly re-
spawning in exposed locations is a tried and true mechanic that maintains an
exhilarating ballet between risk and reward. But how could one translate the
elegant flow of this gameplay loop to a more realistic (or less artificially
'gamey') setting? As Andrew says in the article, you could make more linear
and scripted encounters. Which is fine for story-driven games, but limits
player agency.

If you'd prefer more organic, emergent game-play, there are other options.
Instead of initiating combat only upon the player approaching a set piece,
opening a monster closet, or crossing a trigger, you can instruct enemy AI to
patrol the potential avenues a stealthy player might take and guard the choke
points a speed-runner might attempt to barrel through. From there, you can
temper the utility of the player retreating. There could be speedy mobs you
wouldn't want to turn your back on. Level design that enables flanking —
implement a nav mesh that guides your agents to split between chasing the
player down and heading her off at the pass.

But none of that is objectively superior to more predictable fights. Nor is it
guaranteed to to be perceived as more enjoyable than comparatively random
encounters. Ultimately, what you really should avoid is a ruleset that keeps
players from having fun because the interesting game play loops you intended
to happen end up being trumped by dominant strategies that are obviously
better for approaching the victory condition, but more boring and tedious to
execute.

The actual problem isn't with players figuring out how to exploit doorways.
It's rather that moment when they resign to repeating the same move ad
nauseam.

[0]
[https://news.ycombinator.com/item?id=20663044](https://news.ycombinator.com/item?id=20663044)

------
hosh
This reminds me a bit about Christopher Alexander’s work on architecture and
designing living spaces — as places that shape the potential of human social
and emotional interaction.

Alexander’s pattern language work in architecture came to greatly influence
human interaction design and object oriented programming pattern designs.

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cousin_it
Nuclear Throne solved this problem by having enemies drop health and ammo
pickups which expire really fast. So if you stay at the door and keep taking
potshots, you'll just run out of ammo. The only way is to rush in, shoot,
dodge and pick up stuff at the same time.

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ISL
Give the enemies a radio. The player's goals are probably impossible when the
reinforcements arrive, so the player must be quick.

~~~
usrusr
Tron 2.0 and some other games by the same studio (No one lives forever?) had
"reinforcement buttons" that roughly doubled a monster spawn when one of the
first group managed to access the button. Still a far cry from the "direct
reinforcements to the rear of the player" option that would end any
playthrough quite fast, but a very satisfactory repeated sub-goal.

~~~
pbhjpbhj
Goldeneye on N64 had the alarms which would, IIRC, at least accelerate the
onset of enemy attacks but I think also increase numbers of attackers.

~~~
blattimwind
Project IGI had local and global alarm systems. E.g. with two bases on the
map, alerting the first base would spawn a massive number of soldiers (a
regenerating pool of 4-~15 soldiers) and some other stuff, e.g. tanks, while
increasing patrols in or around the second base or turn NPCs from an idle pose
to a searching pose.

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mcphage
The author's solutions involved making the open arena more inviting, but
another possibility is instead making the hallway _less_ inviting. Maybe an
enemy that appears behind you in the hallway, pushing you forward. Or damaging
floors, or a laser, or conveyor belt, or something.

~~~
twic
There's a very simple Android game called Very Angry Robots, where you
negotiate maze-like levels filled with robots trying to kill you. The robots
aren't very clever, so you could clear any level by taking it slowly. Except
that there's a slow-moving but indestructible robot which can phase through
walls, which enters the level if you're there for too long.

~~~
mrob
Sounds a lot like the classic arcade game Berzerk, complete with the
indestructible wall-passing enemy to hurry you up:

[https://en.wikipedia.org/wiki/Berzerk_(video_game)](https://en.wikipedia.org/wiki/Berzerk_\(video_game\))

~~~
twic
It is exactly that game! I had no idea - that is just a bit too early to have
been part of my video game childhood.

The Android remake replaces the (apparently astoundingly expensive at the
time) synthesized voices with samples of a small child saying "kill the
humanoid", which is if anything even scarier.

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SubiculumCode
As a player I prefer to think of it as the door opportunity.

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friendlybus
Article gets the perspective completely wrong. A space has meaning because a
mind interacts with it. If you see the player as the only mind in a single-
player game, then go make design hurdles and obstacles like an olympic sport.
But videogames can have fake AI minds.

If you design a room from the perspective of a dog that needs to maximize it's
needs/wants/goals/skill/desire, from the perspective of it's mind, then
designing terrain so that the dog can pursue those goals in a way that is fun
for the player and for "the dog" is much more intuitive. The only conflict you
need to focus on is the intersection between the dog's goals and the player's
story-line through the world.

Presuming your game is based on combat, then designing the space so the dog
can maximize (or just play) with it's abilities and perceptions in a fight and
making the room play in fun way becomes more straight forward. You look at the
room you are building from the perspective of 4 paws on the floor and build a
nice overhang or a cheekily placed box so that when the dog breaks it's normal
goals to pursue the player, the most common response from the player (look at
it, or whatever) will be intersected or guided by a fun piece of world matter.

There is nearly no meaning in his world, it exists only to express the skill
of playing a game with no minds, so an emphasis on map control and resources
control becomes more important than interacting with a meaningful behaviour
the game actors produce.

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dexwiz
Reading this article made me think of many of the boss encounters in the first
Destiny. Levels were usually a long, multi part corridor for the first half
and a bullet sponge boss at the end. Many of the boss arenas were poorly
designed with so many spawn points that most cover was nearly ineffective. So
the optimal game play was to stand in the entry way, funnel trash mobs into
the entry and kill them, go out and shot the boss for a bit until the next
wave of trash spawned, retreat to the entrance and repeat. They did get better
with design and started dropping you into arenas to remove the doorway.

I think the designers did fill the arenas with these mechanics to make them
interesting. But so many of the main objectives included a bullet sponge
enemy, that while you were addressing the objective new trash mobs would spawn
in unpredictable places, and usually more than one wave would spawn during the
objective. This made most of the cover feel worthless. Instead it was just as
viable to fly around with you jet pack or super jump, keep moving, and hope to
dodge random enemy fire.

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cmroanirgo
To be frank, I thought this article would be discussing the 'other' door
problem, which arises in multiplayer scenarios. It's also called 'first to the
button' (or post or flag).

The basic premise is: there's a button on the wall and two players are running
toward it, one has higher frame rate the other has lower latency. Which one
wins?

It's a problem that's been around forever & I assume it's taught at uni these
days. Ironically, I didn't find much on Google (nor gamasutra), here's a
similar (but not exact) real world prob:
[https://stackoverflow.com/questions/6241377/multiplayer-
whit...](https://stackoverflow.com/questions/6241377/multiplayer-whiteboard-
race-condition)

~~~
leetcrew
isn't this basically a solved problem (if tricky to implement correctly)? you
have a game simulation update rate that is decoupled from the graphics
framerate and give a local timestamp to every update. then the server compares
the timestamps to decide which action occurred first and updates game state
accordingly. if you make the simulation logic simple enough or pick a
conservative update rate (I believe battlefield is or used to be 10 Hz), you
can ensure that even min-specced machines almost never have to skip a
simulation frame.

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localcdn
I couldn’t find a recording of the GDC 2019 talk about non linear level design
the article mentions. Anyone know why GDC doesn’t post all talks online but
rather uploads a subset of talks seemingly at random?

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anthrojikolp
The real problem isn't the level design, it's that the enemy AI in such games
is not smart enough and as a result can be defeated by simple tactics.

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ErikAugust
I made my way through GoldenEye on 00 Agent this way. I am not sure how else
it could be beaten.

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m3kw9
Make them surprise spawn in like Doom

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yason
I recognise the situation but I've always considered it part of the gameplay.
I mean, how else would you play when the enemies are tough?

In nearly any shooter you will soon learn that if you run into an open space
carelessly you're likely to trigger lots of monsters/enemies at once and that
means you're going to suffer from it. How do real-life special forces
infiltrate a building with armed enemies? Very carefully, and with lots of
cover.

Similarly, in a game you want to kill the enemies in small batches, ideally
one by one, to minimise the risk of getting too much damage. And isn't the
point of an FPS to map the whole level, corner by corner, without taking too
much damage and successfully killing enemies until none are left?

You can balance taking damage with trying to speed up the game if you don't
feel like going slow and secure. And you will learn places where it is worth
taking a bit of damage to obtain more benefits. That's what you will be
continuously balancing as a player, depending on your mood and how well you've
been playing so far, and that's one element to it.

Playing the level the first time generally means slow and conservative
gameplay. Further sessions in the same level will obviously make the player
make more educated tactical choices. A good level will only reveal itself over
multiple rounds of gameplay, and ultimately remain a good level.

In fact, tricks to prevent the player from finding cover by doorways or other
obstacles are usually just irritating. You know it's going to be a hard battle
in that big room ahead, and you know you can't back out to relative safety
after dropping down to the lower level from that higher-level balcony you're
supposed to use to enter the room. In all battles you want to have, at your
disposal, some nearby place that you can retreat to, if you want, if you're
low on armour or otherwise beaten down. If you're doing well you are likely to
be impatient enough to stick with the safe routine by the doorway. This will
let the player balance how conservatively he wants to play at any given time.

It's good to force the player to move around, though. Sprinkling ammo and
health-ups around the level in small batches helps. A traditional scheme is to
make the player fight for optional aids: going down a passage to get the big
health pack or more ammo also means risking hitpoints and using nearly as much
existing ammo to compensate. If you play good, you'll be rewarded with more
than you had before. If you play bad, you just make things worse without
getting any further in the level. But this shouldn't be used as an excuse to
eradicate the locations of relative safety such as doorways that are really
handy indeed when you need them.

Instead of forcing the player to fight without cover your level is much better
off by being of non-linear nature in the first place, allowing the player to
roam to any direction and choosing which sections to take out first and which
accompanying enemies to trigger in each location, because that also gives
enemies some routes to wander behind the player's back. Some of the enemies
can be made to hear fighting and start finding their way to the player while
others can be kept to wait until they see the player. The unscripted arrival
of extra enemies wandering about will make the eventual game dynamic much more
random and convoluted, and opens more choices for the player to make. For
example, "go through the easy wing to find yourself in more trouble at some
point later" vs "start taking the hard enemies down first with less ammo to
avoid the level collapsing into a hellhole later".

Any level should try to maximize the player's ability to balance between
different tactics. Sometimes the player wants to finish off quickly, sometimes
he wants to kill each and every enemy and collect all power-ups and secrets. A
level can become totally different based on how it's played, and a good level
doesn't force that "how".

------
akeck
My intuition is that one can apply these principles in a flipped manner to
design safer schools and other public buildings.

~~~
lolc
Let us all walk around concrete obstacles for fear of an unlikely attack?

~~~
adrianN
Schools turn into parkour training gyms. Might help against youth obesity
(probably saving more lifes than the shooter protection aspect...), but
excludes students with disabilities.

