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I make computer games, mostly small ones, in Java. My favorite games to play are probably Armageddon Empires, Minecraft and Master of Orion II.

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Positional Dungeon Crawlers

Zarkonnen Blog

It's occurred to me that all three dungeon crawler games I currently play have something in common: positioning matters a lot.

Hoplite is literally the only Android game I actually play. It's a simple but elegant hex-based dungeon crawl wherein you must traverse sixteen levels to reach the Fleece of Yendor. Each turn, you can move one tile in one direction or use your limited special actions to jump, bash with your shield, or throw your spear. Enemies are defeated by either moving straight towards them or starting and ending your move on an adjacent tile.

This means that good Hoplite play is all about reading the juxtaposition of your enemies and finding a path that lets you kill them without taking any damage. It gets particularly satisfying when you manage to kill multiple enemies at once.

The Binding of Isaac, both in its original and second version, is all about predicting the movement and attack patterns of your opponents. Some move in straight lines, or jump diagonally, or charge. Some fire shots in bursts or specific patterns.

It actually reminds me of chess a bit: hoppers' jumps are like knights', while the crosswise and diagonal attacks of clotties and clots requires you to superimpose the same pattern onto the screen as you would while evaluating an enemy rook or bishop.

And in Crypt of the Necrodancer, the positional aspect is both in the movement patterns of the enemy - skeletons move every second turn, so you have to make sure you are in the correct phase of the beat - and in the damage patterns of your weapons. In a traditional roguelike, swords and daggers and spears all operate at point-blank range and are differentiated by their damage and maybe certain bonuses. In Necrodancer, a basic sword, dagger and spear all do the same damage, but in a different pattern of tiles. This again makes positioning more interesting - in fact, I'd rather have a normal sword than a titanium (double-damage) dagger.

(As an aside, this held true in real life too - in medieval warfare, the main weapon was the spear and rather the pike. Daggers and even swords were secondary weapons you'd use if you had to. Our modern depiction of everyone using swords is like showing a modern war where everyone is using pistols instead of assault rifles.)

In comparison, other, "classic" dungeon crawlers like Nethack or Diablo make poor use of the fact that they happen in a 2D environment. There are some area of effect abilities, true, but nothing like the positional gameplay you get in the three games above. Positional gameplay is so fundamental to each of them that if you were to reduce them to a linear 1D environment, the gameplay would fold in on itself. They can get away with otherwise pretty simple rules because the 2D environment makes for so many different interesting game situations.

On the other hand, it's perfectly possible to make a one-dimensional dungeon crawler. Look at Darkest Dungeon, by all accounts a deep and engrossing game, whose combat situations are in a 1D environment. But to compensate, it has to have much more complex mechanics otherwise.

I don't think that positioning-based mechanics are easier to develop. They have more complex interactions. But they are easier to understand for the player, and players will have an easier time spotting interesting game moves thanks to all that brain circuitry devoted to visual processing.

In conclusion, I think that positioning-based gameplay in dungeon crawlers still has a lot of unexplored design space, be it through movement and attack patterns, or in other ways yet to be discovered.

Beyond mere survival

Zarkonnen Blog 1 comment

Once you have survived in a survival game, what do you do? You have found or made clothing, shelter, a steady source of food, means to defend yourself and heal yourself. You have mapped the dangers of your environment and can defeat or avoid enemies. What comes next?

What I enjoy about the survival genre is the tension produced by scarce resources and immediate dangers, but this is kind of self-limiting. If the player is able to progress at all, this scarcity and danger will abate, and interest has to come from somewhere else.

Different survival-type games I've played solve this endgame problem in different ways. NEO Scavenger acquires a plot with supernatural elements. Minecraft becomes a sandbox block building game. Resources are still limited but by no means actually scarce. Other games become entirely about combat.

What follows is a proposal how to keep a survival-type game interesting beyond the immediate "I have trousers and food now" stage with less of a shift in gameplay.

Willpower

In nearly all computer games, your avatar or units have infinite willpower and obedience. A few marines in Starcraft will gleefully charge a whole army of Hydralisks, getting torn to shreds in seconds. And your avatar in NEO Scavenger or Minecraft never despairs. As long as you are fed and rested and healthy, you can keep going, no matter the exertion. A bed in a tiny cave in the soil is just as good as one in a beautifully appointed master bedroom. Your clothes always fit and never chafe.

Now contrast that with a realistic assessment of what would happen if you got stranded on a remote island. Apart from the need for nourishment and shelter, you would have to deal with the psychological stress of being alone and the hardships of mere survival. You may end up having to paint a face on a volleyball just to stay sane.

Game mechanic one is willpower: It's a resource that recharges with good rest, good food, good clothes and the experience of beauty. You can use up willpower to temporarily boost your abilities: carrying more, moving faster, working harder. It allows you to keep going when you are tired, or ill, or in pain. You can function with zero willpower left, but it is tedious, dangerous business. You start the game with quite a bit of willpower in the bank, so it's not your most immediate concern. You can spend it to smooth out the bumps when you are doing your best to not die immediately. In the long term, though, replenishing your willpower becomes important.

Experience

Another issue with lots of survival games is that variety is kind of irrelevant. One foodstuff is as good as the next, and your avatar is fine with staying in the same place forever. For the player, discovering new stuff is part of the fun: a new plant, an interesting new landscape, a new item to craft, a different kind of shelter. But because of the mechanics of survival, going exploring is discouraged: you are safer staying in a place where you know the dangers, the food sources, the shelters. The game's rewards structure hence works against the player's desires.

To bring these two in line, game mechanic two is experience points that are gained only from having new experiences. Killing stuff does not gain you XP, nor does crafting or mining. XP is gained by seeing new things (plants, animals, landscapes, artefacts, books) and experiencing them directly: different food, drink, clothes, steeds to ride, and so on. This XP can then be spent on new skills, abilities, crafting recipes.

Together with the willpower mechanic, this should provide in-game rewards for extended play that includes exploration, experimentation, and working to move from mere survival to thriving comfort.

A Prototype

I might code up a really stripped-down prototype for showing off these two mechanics in a simple survival game. The prototype would track hunger, thirst, health, willpower, and XP. You would have to find food, water, clothes and shelter, all of which available in both aedequate and willpower-boosting variants. And you'd start out with zero crafting recipes, but could "buy" recipes with XP.

Dungeon Granularity

Zarkonnen Blog

After it was linked on MetaFilter, I've been playing a fair bit of Dungeon Robber. The game is a pretty faithful implementation of the random dungeon generator from the D&D first edition dungeon master's guide, as recently turned into a poster.

In the game, you start out as some hapless dungeon delver equipped with nothing but a sturdy cudgel, attempting to extract some treasure from the dungeon without dying.

The dungeons are very random. There is no balance or logic: the first room you enter could contain a skeleton that kills you or a priceless ruby. More likely, the first ten rooms you traverse are empty. As the author states, "By rolling dice according to the instructions, you could generate a dungeon which was illogical, arbitrary, super-lethal, and which often didn't even produce useable results."

Despite all this, I think the game is really fun. Granted, this may be due to some combination of masochism and nostalgia from my end, but my thesis is this: most dungeon crawlers have the wrong granularity.

Your traditional CRPG dungeon crawl subdivides the dungeon into tiles of roughly a meter square. Creatures usually occupy exactly one grid location. This means there are lots of details present about the shape of the room and everyone's exact relative positioning. But does it matter if a room is 5x5 or 5x7 tiles? Not nearly as much as whether it contains one monster or two.

As I wrote in the post on granularity, the commands you can give to a game should be at the same level of granularity as the meaningful decisions the game needs you to make. As a corollary, the information presented should be at the same level of granularity. Does it matter what exact size the room is, if it contains only you and two orcs? No. Does it matter where the orcs are relative to you? In a lot of games, it actually does not.

Dungeon Robber is so enjoyable because it strips away these superfluous details and just presents you with the choices that matter: attack the orc or run away. In doing so, it also opens up space for other choices: the game lets you parlay with the orc, or bribe it, or try to sneak past. Most CRPGs don't give you these options, because they spent their efforts on modeling and communicating the shape of the dungeon.

So here's the choice: Either do away with the irrelevant information about room layouts and monster positioning, and concentrate on implementing more choices that matter - like Dungeon Robber (and SE:SS, in a way). Or make room layouts and monster positioning really matter.

There's places where games do this: NetHack lets you tunnel through walls making the relative layout of rooms matter a bit. Shadowrun Returns has a cover system that makes positioning matter a lot. In Bargains, we're trying to make spells that have a positioning-based component, like fireballs that are shot not from your hands but from the most nearby brazier.

Still, this is pretty weak fare. My concept for fixing it: Viewing a dungeon not as a sequence or network of encounters (fights, puzzles, etc), but as a three-dimensional structure for you to interact with.
There's a lot of things relating to the shape and "consistency" of the dungeon, and the player's interaction with it, that current CRPGs do really badly:

  • Hidden Doors: These are either blatantly obvious plot-points or rewards for people willing to bore themselves to death by using "look" on each wall tile in every room.
  • Secret passages: Again, these are rare. Maps tend to be too cramped for them, which makes their inclusion obvious.
  • Crumbling floors that may fall in and dump you one level down.
  • Vertical drops you have to use a rope or ladder to get down
  • Steep rugged slopes you have to scramble up or down
  • Narrow doorways or cracks you can only fit through by leaving behind your armor and backpack
  • Ledges to jump down on enemies from
  • Crumbling brick walls that can be brought down with some carefully placed hammer blows, at the cost of alerting everyone to your presence, and making the ceiling rather less than stable
  • Tables or shrubs or rubble to crawl behind to pass unnoticed
  • Narrow ledges to inch along
  • Shafts and cave passages too narrow for most people to pass
  • Waist-deep water that slows your movement
  • Hidden entrances only uncovered at low tide
  • Thickets you have to force your way through, making noise and causing exhaustion
  • Dungeon inhabitants with more complex behavior than "attack", such as running away, but fighting when cornered
  • Interesting and impressive architecture, instead of a series of rooms: giant underground caves, a bridge spanning an abyss, an underground city, a cluster of old towers, connected by crumbling bridges, the remains of an ancient city, half-buried in the soil, jungle growing over it

This may seem like a big mess of different things, but it actually boils down to a few well-defined features:

  • A map made of 3D blocks that's not segmented into levels
  • Destructible map blocks
  • Partially passable map blocks (narrow entrances, ledges, rugged terrain, foliage)
  • Tracking noise and visibility

Granted, none of these features are easy, and a lot of them have implications for the creature AI, but I would love to see a game that focused on them: no fancy graphics, simple UI and combat, no involved plot. Just big meaty 3D hunks of dungeons, left for the player to unlock with their wits.

Granularity

Zarkonnen Blog

Commands in games should be at the same granularity as the meaningful decisions you make. I just finally got around to finishing the new XCOM game, many months after everyone else, no doubt. I kind of wanted to make it last, though, because I think it's an amazing game. I also recently had the pleasure of reading Polygon's The Making of XCOM's Jake Solomon.

What struck me about the article was all the things that Jake wanted to put in, as a die-hard fan of the old X-COM, but ultimately had to leave out or simplify: detailed action points, randomly generated maps, large squads.

XCOM ultimately shipped with a system that allows no more than two actions per unit per turn: you can move twice, or you can move once or shoot. There are some special abilities that bend and break this concept, but there is no major deviation. Each map is hand-built, but there are many. And the maximum number of soldiers you can ever deploy is six.

Even before the game was released, lots of fans of the original games complained about how the new XCOM was dumbing things down. It's interesting that the original design for new XCOM included all the complexity whose absence the fans now lamented. But while veteran X-COM players at Firaxis could cope with the complexity, it was nightmarish for everyone else. Ultimately, much of it was removed.

I'm not a old-X-COM kind of guy. I think it was a good thing the game was "dumbed down". Why? Granularity of decisions.

I've played, or tried to play, the original X-COM and a bunch of more faithful adaptations. In general, each unit gets lots of time units, and each map tile moved costs one unit. Shooting, depending on the weapon and the mode, costs a number of units. This gives you the freedom of, for example, moving two tiles, firing a quick burst, then moving again. You can't do this in new XCOM. You can move and then shoot, or just shoot, or (with some special abilities) shoot and then move or shoot twice.

I've found I don't mind the restriction, though. In fact, I find it more realistic that you can't do too many things in sequence with no interference from the enemy. The reason I don't miss it, I believe, is that in a particular tactical situation, there are a number of actions that make sense: Things like moving forwards into new cover and taking a shot, or moving quickly in an attempt to outflank the enemy, or staying behind cover and blasting away, or waiting for the enemy to advance.

A coarser-grained system of choices can support these actions just as well as a more fine-grained one, but doesn't burden the player with as many how-long-is-a-piece-of-string type questions as "should I advance by one more tile", and also reduces the annoyed feeling of being exactly one time unit short of being able to do another useful thing. With fine-grained actions, the question of what exact sequence of actions to take is much more complicated than the question of what kind of tactics you want to pursue, leading to a whole bunch of mental legwork and frustration that adds little or nothing to the game.

In short, the commands you can give to a game should be at the same level of granularity as the meaningful decisions the game needs you to make. If the commands are finer-grained, you spend a lot of time executing the same pattern of small steps to achieve a particular effect, or doing mental arithmetic to figure out if you can squeeze just a little bit more efficiency out of your choices. When your choices matter only in aggregate, it's also easy to lose track of what you're doing.

Of course, if the commands are too coarse-grained, a different kind of frustration sets in. This is perhaps less common in strategy games, but extremely common in RPGs and first-person games. In the former case, when you are caught by the king's guards stealing the Stone of McGuffin, the game may not give you the option to explain that you need the stone to defeat the Ice Dragon, or to throw the stone into the ocean below the hover-keep, to be retrieved later. And in first-person 3D games, your badass character is often stymied by waist-high fences: you can only jump straight up, and you can only jump 40 cm, but the fence is 60 cm tall! Any human being in possession and control of reasonably functioning limbs can scramble over an obstacle like that. Having the fine granularity to give the command "scramble over that fence" would be nice.

In conclusion, figure out what the granularity of meaningful decisions is for your game, and model your game at that level of detail. This is something I've tried very hard to follow in SE:SS - the game asks you to make lots of decisions, but it tries hard to make each of them meaningful, and give you as many meaningfully different options as possible.