Tuesday, June 30, 2015

@Play 82: The Talks of the International Roguelike Developers Conference US, 2015

One month ago was the first annual (we hope!) U.S. metting of the IRDC, The International Roguelike Developers Conference, organized this year by Todd Page! I was on hand (slightly incognito -- if you were there I was the one who looked the most like Cousin Itt) and, after reviewing the archives of the talks put together by Kawaii Dragoness I have managed to compile notes on the presentations presented by the presenters present. Those notes follow. By the way, the European IRDC just finished up, but considering the lateness of this installment I think I'll leave it to someone else to write up those.

I believe strongly in hyperlinks, so before we get underway, here are some useful sites: IRDC US Tumblr - Ultima Ratio Regnum's page on the Euro IRDC - IRDC US's Twitch TV page - Logo Surströmming's YouTube page, where some of these talks are archived.

The talks were held at Georgia Tech university in scenic downtown Atlanta, and Saturday and Sunday stretched from 10 a.m. to around 5 p.m.  A Starbucks was in easy walking distance, as was the hotel that some of the guys were staying at, to which we retired Saturday evening to discuss matters of game design.  Kawaii Dragoness mentioned hotel room Soul Calibur sessions stretching late into the night.  (Of recent versions, unfortunately; to me, it's not Soul Calibur if it's not on a Dreamcast.  There was a time when Ivy's breasts weren't bigger than her head goddammit.)

Most of went to Ray's New York Pizza for lunch Saturday where, flush with the recent news that Freehold Games' Sproggiwood was to be featured on the iOS App Store, Brian Bucklew generously paid for everyone's food!  He also knows a great deal about board games, I discovered Saturday evening!

For Sunday's lunch, the group split up; I went with the younger participants to a nearby Five Guys where, unfortunately, we were rained in by one of Atlanta's ludicrously sudden and intense thunderstorms.  It was there, by the way, that I made the discovery that fresh jalapeno slices should be treated with great respect....

Miscellaneous games and projects overheard mention while at the conference: Infra Arcana, Necklace of the Eye, No Man's Sky, Pixel Dungeon, Heavy Axe, the Doom procedural level generator OBLIGE, Artemis Bridge Simulator, Alien: Isolation, Chromehounds and the Roblox game Mad Murderer.

1. Todd Page, organizer of IRDC US 2015, Opening Remarks YouTube
Getting us underway....

2. Jeff Lait, star roguelike developer and many-time 7DRL participant: "An Apologia for the Berlin Interpretation/Why Balance Is Terrible/An Algebra Of Roguelikes" YouTube


Covers a lot of varied territory, including balance issues and dungeon generation and representation in memory. Lait created POWDER and many 7DRL games, many of them very interesting.

Of particular interest is his discussion of non-Cartesian representations of dungeons, that is, not representing the dungeon as a 2D, XY-based map. I found that fascinating, since it gives some of the implementation details of Jacob's Matrix, a 7DRL Lait made a few years ago in which you explore a non-Euclidian space.  (I wrote about it some time back in one of the @Plays on 7DRL....)

Remember Portal? How the world you viewed through a portal looked just like the world outside of it? Like that, except, when you see through a portal in Jacob's Matrix, you don't see that it's a portal. Different parts of the world of Jacob's Matrix can be connected together in strange ways, and what's more, portals can even rotate your perspective, meaning that "north" is not necessarily the top of the screen, and can in fact change for you depending on what parts of the dungeon you've been through. You can return to your starting point after exploring for a while by a circuitous route, but you might not recognize it, because your perspective may have rotated.

It's an amazing, mind-expanding game, in fact Lait mentions in the talk that it was *too* mind-expanding and confusing, and so toned down those aspects in later games he's made with that engine, as well as explaining some facts of how it was made, without using a traditional two-dimensional array for world representation. Some technical details of his implementation are presented.

I also appreciated his comments about rare content, aspects of a game that don't reveal themselves after one or even many plays, that only show up at unusual moments, giving as an example NetHack's pit viper joke. And it also claims that balance is overrated, that unbalanced moments may make a game more challenging, but they also make it interesting, and adds texture to the play, an evocative term that I've found myself using sometimes as well.

Jacob's Matrix, and many of Jeff Lait's other games, can be found here. His POWDER can be found on the iOS App Store here.

3. Lee Djavaherian, tinkerer and hardware hacker: "A Tiny Room In A Tiny World" YouTube


Lee brought along a small toy treasure chest that, he reveals, actually itself completely contains the hardware used to play a roguelike game! It was made using a small, ultra-low-power microcontroller processor that runs on solar cells. It has no display but offers its display through a serial port, which can be viewed through a terminal emulator. It even communicates using Morse code.

He also goes over some of the history of computer roleplay gaming, leading up to the Video Game Crash of 1983. His mentioning of the Apple II game system EAMON is particularly interesting. In my alternate life as Metafilter's JHarris, I once made a post about EAMON. If you want to know more, it is here.  EAMON is a particularly twisty maze of passages; there's a website about it here.

Many aspects of the device's construction are discussed and illustrated. I'm still not sure exactly how it works, he didn't demonstrate it, I think due to time concerns. But, fortunately, he's put up a page discussing the project.

4. Brian Bucklew, co-founder of Freehold Games: "Data Driven Engines of Qud And Sproggiwood" YouTube


Freehold Games is an up-and-coming developer, and during the conference Brian Bucklew discovered that their Sproggiwood was due to be featured on the iOS App Store. (It's also on the Google Play Store.) He discusses Qud's early history and its class construction, especially regarding inheritance and behaviors, and other implementation details.

One goal of his in Qud's design, he notes, is his aspiration to remove the code as a barrier to inspiration, an interesting goal that I think may be ultimately impossible depending on how you interpret it, but still you can get quite far. He describes this in terms of how the ease of adding items and features to the game scales well as the game's complexity increases, so the 4,000th item added takes the same effort as the fifth.

Caves of Qud, which you can download and play from their website for free here, sounds amazing, and I have no idea why it's been off of my radar for so long. I had a chance to speak a little with Brian, and can confirm he's an extremely nice individual. And he knows about a lot of Eurogames, which is a sign of a well-rounded game designer. It is so nice to hear that he and colleague Jason Grimblat (see later) are making a go at it in the lottery of the App Store.

5. Brett Gildersleeve, author of Rogue Space Marine: "Rogue Space Marine Development Inspiration" YouTube


Brett Gildersleeve talks about Spelunky's level generator (which has a web page describing and demonstrating it) and his own game Rogue Space Marine. The stuff on Spelunky is terrific, and this should be watched for that reason at least, but it's also worth it for glimpses of the play of Rogue Space Marine, which actually introduces aspects of bullet dodging shooters into a turn-based roguelike. Watch and be amazed! Anyway, what Rogue Space Marine and Spelunky have in common is a mixture of pre-fab and randomized level generation, as a way to better ensure interesting situations.

The 7DRL page for Rogue Space Marine, which includes a 30-minute play video and a download link, is here.

6. Jim Shepherd, developer of Dungeonmans: "The Procedural Battlefield"

Leading off with a (joking?) idea for a new game called GRIZBAND, where you play as a bear. Jim Shepherd designed Dungeonmans, and talks about designing interesting play areas, and the uses of pre-made areas vs procedurally-constructed areas, which may be nominally different every game, but may not produce interesting situations. Brought up is the design of Dungeonmans, and mentioned is the sainted name of Dwarf Fortress. In practical matters, Shepherd suggests, when creating those interesting pre-made areas, not making an editor program, but using raw text files....

BTW, I can vouch that Shepherd's game Dungeonmans (Steam, $15) is entertaining and interesting! It's got roguelike play, but of particular interest is how the focus is on the world around the player, and the metagame where you're improving the fortunes of an adventurer academy as character after character advances through a randomized world.

7. Jared Corduan, mathematician: "Math-like Roguelikes" YouTube


He presents four roguelike-related puzzles from the realm of recreational mathematics for developers and viewers to think about. The first is John Horton Conway's "Angel And Devil," otherwise known as the Angel problem (Wikipedia), involving hemming in an angel on an infinite checkerboard. The others are "Lemming On A Chessboard," "Homocidal Chauffeur," "3-Way Duel" and "Chomp."

8. Sheridan Rathbun, developer of Barony: "Barony Post-Mortem" YouTube


Barony is a first-person perspective roguelike that offers four-player cooperative play! His talk is a personal story of trying to make it as a young, up-and-coming indie roguelike developer. It is available on IndieGameStand and Desura ($7), and is soon coming to Steam! Its homepage is here.

9. Bob Saunders, author of Approaching Infinity: "Infinite Gameplay" YouTube


Discusses his game Approaching Infinity ($40), a "space roguelike" with both personal exploration and spaceship combat sections published by Shrapnel Games. In particular, there's no limit to the game size and there's no cap to the player's statistics. An amusing aspect of his game, he reveals, is a planet where the terrain spells out "Darmok and Jalad at Tanagra," a reference to a particular Star Trek: The Next Generation episode. Stay geeky, Bob Saunders!

10. Cameron Kunzelman, developer and 2CI Fellow in New And Emerging Media at Georgia State University: "The Artisanal Rouguelike"

Cameron Kunzelman did a talk about "The Artisanal Rouguelike" about indie roguelike game constructions before and now. A major theme of his talk is procedural generation, which is turned to more and more often by developers of all levels as a way to decrease the effort needed to create content.

Kunzelman has a blog, at thiscageisworms.com, which not only talks about his game releases but also features writing on other games, including some non-roguelikes, which are rumored to exist out there somewhere.

11. Eben Howard: "FOV and You"

Eben Howard's talk "FOV and You" is about line-of-sight algorithms, showing off a variety of them, their uses and drawbacks, with a custom-written Java applet, and also covers the use of a roguelike library, Squidlib. It should be of immense interest to most traditional roguelike developers, especially new devs who are interested in learning about the fundamental algorithms of the genre.

Howard has a website, squidpony.com, where he posts news about the development of SquidLib.

12. Adam Boyd, former moderator for r/pixeldungeon: "Everyone's @ Home"

Adam Boyd is (was?) a moderator on the popular subreddit for the game Pixel Dungeon, and presented a talk about the maintenance of a community devoted to a roguelike game, and the interplay between the developer and the fans (the dev added an area to his game and other features based on memes in the community). Pixel Dungeon is now available on Steam ($5), desktop systems (free, requires Java), Android (free, but w/in-app purchases) and iOS ($3)

13. Jason Grimblat, co-founder of Freehold Games: "@ Meets ?: Collaborative Storytelling Through Procedural Generation" YouTube


Beginning with video of players going through Freehold's post-apocalyptic roguelike Caves of Qud (the video carries the subtitle Antelopes vs. Molluscs — note, the video doesn't actually begin until the 5:30 mark, so you may want to skip to there), the talk moves into how the players took random details provided by the game and built them into a backstory, an explanatory narrative that fit the supplied data. This is of course part of the appeal of Dwarf Fortress. Grimblat makes a distinction between developer stories, pre-written content for players to consume, and player stories, which they create themselves.

He then describes how collaborative storytelling works in Jason Morningstar's wonderful pen-and-paper game Fiasco, which is all about the constructions of these kinds of narratives, and asks what hints we can glean from it. Fiasco is particularly relevant because it doesn't have a referee or GM to author a scenario for the players to inhabit; the players work together to construct those elements. (By the way, have you heard of Fiasco? It is not a roguelike, but it's wonderful! While it's not free itself, it has all these free supplements....)

The final section has to do with the themes of the classic post-apocalyptic RPG Gamma World, and how they were adapted for Caves of Qud.

14. Rob Parker, researcher for the University of Waterloo: "The Role Of Permadeath In Roguelike Games"

One of the most-associated features with roguelike gaming is permadeath, the idea that player only has one shot at each play and has to start over if his character dies. He talks about permadeath in content of player learning, content unlock systems and procedural generation. Rob Parker mentions, by the way, that he's working on a roguelike based on David Lynch's movies and Laura Dern's career. I have difficulty imagining such a thing, and am eagerly waiting to see what he makes.



@Notes:

Sorry this one took so long, building links takes time and energy.  I'd like to call out to anyone with experience with the Japanese game Rogue Hearts Dungeon: does anyone reading this have experience with it?

Sunday, June 14, 2015

EXTRA: Junethack

Just a reminder going out that the 2015 Junethack NetHack tournament, covering a wide assortment of forks, is currently in progress.  Even if you're bored with NetHack, there are some interesting versions up there, especially dNethack (which has nine new-fangled "alignment keys") and, for those who like an older style of game, NetHack 1.3d.

Sunday, June 7, 2015

Upcoming: @Play 82 on IRDC US 2015

I'm putting the NetHack variant article on hold (which has taken a while as I think abou it and mutated a bit) and going to instead write about the talks of last week's IRDC US and the attendees and their games.  Hope to have this up later today, which probably means it'll be up in another week or something.

Tuesday, May 26, 2015

International Roguelike Developers Conference, Atlanta GA

It's looking like I'm going to be at the International Roguelike Developers Conference in Atlanta, GA, USA this coming weekend!  I got back in touch too late to do any presenting, but I should be there.  If you're going to be there too, you'll know me as the guy with absurd amounts of hair and wearing a Cthulhu shirt.

(BTW, money is going to be tight for me there, so donations are welcome, in cash or food.  Food especially!)

@Play is taking a while again, something that paying work continues to get in the way of.  More news there when it happens, I am hoping to get the next thing up before the conference.  If it doesn't, the next thing may actually be a recap of the conference....

Saturday, May 16, 2015

EXTRA: Roguelike Radio celebrates 100 episodes!

The newest episode hasn't been posted yet, but Darren Grey just announced it on his Twitter feed.  When it appears, of course, it'll show up on the Roguelike Radio blog.

@Play 82 is still in the works.  Doing something on all the Nethack variants turned out to be too big a bite, so I'm looking into ways to usefully lessen the scope.  Please stand by.

But not literally.  You might get tired.

Tuesday, April 28, 2015

EXTRA: Bay12 Games (of Dwarf Fortress) has a Patreon

Extra thing for people reading this, Bay12 Games, half of which is the amazing Tarn Adams (who I interviewed before for Gamasutra) has started a Patreon to help secure the future of Dwarf Fortress.  It is a worthy goal I believe: I feel strongly that DF is one of the most important games of our generation.

It only takes a dollar a month, less than a cup of coffee reminds spokesdwarf Urist Struthers, to feed and clothe dwarf child Urist McDestitute and her 39 cats in the manner in which they are accustomed.  If you have a couple of bucks to spare each month, why not shoot them to the dwarfs, I'm sure it'll be of great solace to them in the trying, goblin-besieged, elf-annoyed, werewolf-cursed, demon-beset times ahead of them.

Sunday, April 26, 2015

@Play 81: Rogue's Item ID in Too Much Yet Not Enough Detail

Last time I said that the least-copied feature of Rogue is its item identification system. Of the horde of "roguelike" and "roguelite" games now flooding Steam, very few think to adopt this aspect. Darren Gray, who I'll have you know is pretty sharp on roguelike ideas generally, suggested that people participating in the Seven-Day Roguelike challenge don't bother implementing an item ID system.

Well, I'm here to make an attempt to argue against all that. Rogue is probably the most tightly-designed computer game I know of (and I know of over a thousand), and every aspect refers, in some way, to another aspect, no part of it can be considered in complete isolation from the others, and that includes item identification. I think not only does item identification add something interesting and substantive to it, but that it ties the rest of the game together, that it's really a part of a whole with the other things that make Rogue fascinating, and that the things it adds are not easily replace with other features. But, as with everything else in your design (if you aren't a designer then bear with me), you shouldn't include item ID thoughtlessly: instead, you have to work carefully to make it fit in with the rest of the game, in order to get the greatest benefit from it in terms of depth of player choices. But this is just like everything else in your game, so really it's not any different from deciding what powers your monsters should have or whether you should have a food clock or not.

The core idea is that items in an identification system, the things you collect in the dungeon that go under the increasingly-overused name loot, can have hidden properties. You don't know everything about the objects you're carrying at first sight. Some things about them are known from casual observation, like what general type it is (Sword? Armor? Potion? Ring?), but for some things there's an additional descriptor, like a color (pink potion) or material (lapis lazuli ring) that extends across a hidden class of items. Many items have individual properties themselves that have to be discovered uniquely for each one, like plus or curse status, but for this discussion we're concerned about the descriptive classes of items, not miscellaneous aspects.

Item ID, Fantasy Literature, and AD&D

The idea that magic items may not be known to the player immediately on finding is something that dates back to the roots of fantasy role-playing gaming: fantasy literature.

Sainted Gary Gygax drew from many sources when inventing (with Dave Arneson) Dungeons & Dragons. But a common thread running through a lot of it, something that if you asked me isn't played up nearly as much these days as it should, is that magic is mysterious. Even to a wizard, spells are dangerous business, not always working as you expect. It doesn't make sense that a Level 1 Rogue Muggle would be able to recognize a Sword of Casual Dismemberment on first glance, or even thirtieth.

This is of course another intrusion of that persistent game designer bugaboo, realism. Making appeals to reality is doubly damned these days, first for being inconvenient to play, second for being outright ludicrous in a genre where people throw around fireballs, monsters breathe fire, and gold never seems to lose its value despite the hundreds of thousands of pieces PCs exchange for their diamond swords. And yet, you can never wholly discard realism. After all, we meet Harry Potter properly first, not as a wizard himself, but as a dejected adoptee of non-magical caretakers. Bilbo Baggins is a relatable character, not because he's a Hobbit, or he might have a distant fairy ancestor, or he has a sword named Sting or a ring of invisibility, but because we meet him in a hole in the ground, surrounded by comfortable, normal furnishings. If you're going to author fantasy – and make no mistake, fantasy game designers are authors whether they want to be or not – your work will be more understandable if you have some realistic basis behind it, or at least a logical basis.

(Note 1: I mentioned the list of Gygax's inspirations for D&D, the famous 1st Edition DMG Appendix N, in a previous column. I was inordinately pleased to see that it has returned to the game, with additions, in the form of D&D 5th edition's Appendix D. Note 2: This plea of mine, for play mechanics that at least have some root in realism, it's something that matters more than just the subject of this essay. I might write a column about it later, it's a far-reaching concept.)

Which isn't to say that magic shouldn't be strange and exotic, no, just the opposite. Part of the job of the magic system designer is to interface the realism needed to be understandable, to be relatable, with the wonder of magic, to which it is fundamentally opposed. Reconciling these things is (and should be!) a hard problem, and how you go about it reveals a lot of what you're about as a designer. I could name names here, revealing examples of games that I don't think do it well. There are lots of them. But I prefer here to show by example, showing off a game that does it right. And hey, that game is Rogue itself, and its magic system basically is its item system.

Speaking of Gygax's Dungeon Master's Guide.... Have you ever read the magic item descriptions in the back of it? That whole book is amazing. Whatever you think about it in terms of playability as a game (there's plenty good and bad if you can sift through it all), you have to admit that it's brimming with joy and full of ideas, hundreds of ideas. Its magic item lists are terrific. Of course all the editions of D&D provide a certain amount of fun just to flip through, to read about dozens of strange, bizarre and enchanting gizmos, but the 1st Edition book is unquestionably the best, in terms of both ambition and range. (Note: each subsequent edition bled a little more of that joy out of it. Don't look for it in 4th Edition.)

Anyway, I bring the list up because of a special kind of item that's spread through the magic item listings, intermingling with the more useful devices, and those are the bad items.

Alongside listings for things like sword +1, +2 vs. magic-using and enchanted creatures (I like to imagine it like a long, sharpened spork) is sword +1, cursed. Although it's a +1 sword, and thus "one better," in a Spinal Tap sense, than an ordinary weapon, the sword magically compels the wielder to fight to the death in all battles, which isn't a recipe for long survival against dungeon monsters. It's an item you're really better off without. Then there's the plate mail of vulnerability, which "appears to every test to be magical +1, +2, or +3 armor," but is actually cursed, carries a protection penalty, and immediately falls apart when struck on a natural roll of 20. Then there's the shield -1, missile attractor, the talisman of yearning (which tries to make the wielder drown himself), the vacuous grimoire (which permanently sucks some of the reader's Intelligence and/or Wisdom scores into it), the stone of weight that NetHack players will recognize as like a lodestone, the potion of delusion, the rug of smothering, the scarab of death, and so on. All of this is just from a casual scan; there's plenty more. Pretty much every baneful object in the 1E DMG mentions what other, helpful magic object it's indistinguishable from.

The origins of CRPGs were recreations of pen-and-paper RPGs. And we've covered before that Rogue's closest analogue was to the random dungeon generation tables in another of 1st edition AD&D's marvelous appendices. But most computer fantasy games, for one reason or other, didn't try to simulate this aspect of the game, the presence of bad items. Part of the reason was likely technical, for a bad item can only have a chance of inflicting its badness if a player decides to use it, and that depends on disguising it, which is an extra layer of complexity to add to a game running on limited hardware.

But it should be noted... "because that's how D&D did it" isn't always a good justification for including something in your own game. Rogue's random item system is arguably better than 1E D&D's! Effectively, cursed items in D&D are impossible to tell apart from their helpful lookalikes until triggered, even if one has been seen before. They are basically an elaborate screwing-over mechanism, provided by Gygax to the DM, to help keep metagaming players in line. ("A magic bowl? I've seen one of those before, dibs!") Such items have no good purpose in a roguelike game.

Item ID in action

If you don't have substantial experience with Rogue this article might seem a bit esoteric. The following narrative is intended to give you some idea of how random items work during play. Our hero Rodney the Rogue enters the dungeon at the top level and begins exploring....

LEVEL 1: He finds one unknown potion and two unknown scrolls of different types. He doesn't do anything with them yet. Not much to say yet.

LEVEL 2: The monster opposition is still fairly light. A ring, a wand and a longsword are found. The player switches from his starting +1, +1 mace to the longsword; it's +0, +0, but not cursed. On the average, this a slight improvement. If it had been cursed he would have to rely on random items to drop the sword.

LEVEL 3: This is the first level with Giant Ants (in some versions called Rattlesnakes). These can drain Strength (the sole attribute score) on a successful hit. Two more potions are found here, and two more scrolls, and a food ration. One of the potions is of the same type as the one found on Level 1 (they're both "plaid," however that works), and he also now has two of one type of scroll (they have the same title, something like "swerr mep"). Rodney makes the decision to test-ID one of the scrolls, hoping it might be Identify (the most common scroll). It is! He wisely uses it on the ring (the hardest kinds of item to figure out) and finds out it's a ring of Teleportation. These are cursed and annoying, but potentially a lifesaver. He keeps it in his pack, but mentally notes when he runs out of room it's high priority for trashing.

He also tries one of the duplicate potions, which provides the message "you feel much better." The potion is of Extra Healing; even though he was fully healed when he drank it, Extra Healing potions raise your maximum hit points by two in such a case. That's a nice bonus, but he decides it's better to keep the remaining potion in reserve for emergencies. Later on, when monster attacks do more damage than an Extra Healing potion restores, he'll drink it for further maximum HP. Healing potions also curse confusion, blindness and hallucination. Blindness is the big one there, one usually wants to see that ended as soon as possible, so it's worth hanging on to one until the potion of blindness is discovered.

LEVEL 4: The new monster here is Orcs, which aren't too much trouble. Rodney finds another ring, two more potions, and one more scroll. He's now carrying 18 items, and maximum is 26; not tight yet, but it's getting there. The potion is a duplicate of one he's carrying so he drinks it. "you feel very sick", and he loses three points of Strength! It was Poison. This puts his Strength down from its starting 16 to 13. This isn't a huge problem yet, but with Giant Ants around the Strength loss may continue. A Strength of 6 is the trouble zone, that's where penalties begin to accrue. (He did lose some combat potency though, because Strength 16 provides a +1 bonus.)

He drops the duplicate potion of Poison and tries his last unknown potion, and it turns out to be Raise Strength. That was a mixed blessing. It puts his Strength back up to 14, but if he had drank it before drinking the Poison his Strength would have gone up to 17. But what's more, his "natural" strength (that is, the highest your Strength has ever been in the current game) would also have gone up to 17. The difference is what happens when a potion of Restore Strength is drunk; it restores up to natural Strength. When he does find a Restore Strength potion now, he'll end up with 16 instead of 17. It was bad luck that he drank the Poison before the Raise Strength.

In Rogue these things happen all the time. One cannot let himself get worked up about what could have been if there had been no way to know. Of course, he could have spent his spare scroll of Identify on one of the potions. But now thinking about it Rodney is reminded he has an unknown ring, and tries the Identify scroll on it to discover to his delight that it's a ring of Slow Digestion, one of the most valuable rings. Once put on this cuts food consumption by 50%, significantly reducing the pressure of the food clock. It's a good thing, actually much better than having a Strength of 17. Having good identification priorities tends to work in a player's favor in the long run.

LEVEL 5: The new monster is Zombie, still not a huge problem. Treasure found on this floor is two new scrolls and a suit of Chain Mail. That's probably going to be better than the +1 Ring Mail Rodney began with, but when he tries it on he finds to his dismay that it's cursed and -2! His best option now, Rodney reasons, is to test ID the new scrolls.

Three possibilities will free him of the armor. a scroll of Remove Curse will lift the curse and let him switch back to his Ring Mail, which is one point better than the -2 Chain Mail. Or a scroll could be Enchant Armor, which would raise the Chain Mail to -1, the same power as the +1 Ring Mail, and also lift the curse. And it could be Protect Armor, which wouldn't change the plus or power, but would lift the curse, and also protect the Chain Mail from erosion from rust traps and Rust Monsters, who will begin appearing on Level 9. He reads them both: the first produces the message "you hear a high-pitched humming noise". It was Aggravate Monster, a bad scroll, but all it does is wake up all the beasties on the current level and make them want to attack the player, which is not a bad thing on such an easy level. Really, it's a blessing that it was discovered among such innocent surroundings. The other is an enchant scroll - but it's Enchant Weapon. Rodney's Longsword is now +0, +1. Not bad, but he's still stuck with the armor for the time being....

And so the game continues. Rodney is an experienced player, so as he decides whether to use-test items he keeps in mind all the things that haven't been discovered yet, in order to minimize risk. The worst of them all is the potion of Blindness, which at best means drinking a Healing potion to immediately cure, and at worst makes the game unplayable for several hundred turns, causing the player to get beat up by monsters he can't effectively run from because he can't see them while also taking a big hit to hunger, because you can't effectively explore what you can't see. The beginning of the tough monsters is Level 13, home of the Trolls (although Centuars can hurt before then). A blind player will probably die if he meets a Troll, so it's best either to discover Blindness before then or to abandon use-testing potions there. If they aren't known by that point, he'll probably try to use Identify schools on potions from then on, until Blindness becomes known.

He's conflicted about that wand in his inventory. It's usually pretty easy to identify wands, but the problem is, if it's Polymorph it could be a game ender if the dice don't roll just right. On the other hand, if Rodney stood on a scroll of Scare Monster and created an extremely hard enemy with a wand of Polymorph, he could gain a huge windfall of experience points without much trouble. This is still risky (if the monster's new form is Dragon then Rodney will get fried), but the prospect of getting free experience quickly is enticing enough that some people will throw caution to the wind. Maybe the danger could be minimized if the player were standing near the stairs? And so on.

What They Did, and Didn't

This is the system I described last time: each kind of magical item has an obvious specific description that are randomized each game. Potions come with colors, patterns and other descriptions, for instance, and even without using them, if you find two blue potions you know they're at least the same kind. Scrolls, wands and rings work similarly. You can find out what items do conclusively with a scroll of identify, or sometimes just from using them, or sometimes speculatively, where the game will ask you what you want to call that type of item. If definitely identified that class of item will be permanently named for the rest of the game; if known speculatively it can be renamed later, although if it's later conclusively identified the definite name will overwrite the guess.

The most interesting thing about the system, to my eyes, is its originality. No idea emerges from whole cloth, and every thought a human being has ever had has had antecedents, inspirations, foundations. But it didn't originate in AD&D, whose bad items, the Dungeon Master's Guide says, are indistinguishable from the good ones, even by magical means. According to the descriptions given there, no amount of examination will be enough to distinguish a bowl of commanding water elementals from a bowl of watery death. If divination could do the job the DMG doesn't say, effectively leaving it up to the tender mercies of the DM.

The way Rogue does it makes for interesting situations, of the type demonstrated in the play example above.  It gives the player an additional way to demonstrate skill, and thematically it makes a point about the nature of magic. But a lot of games don't do this, they don't bother to offer item identification as a subgame, and it's often not bad that they don't!

If you implement item ID badly, what you end up with can be distracting, or annoying, or even frustrating. If all items are identified immediately on the point of use (Mystery Dungeon games sometimes do this in bonus dungeons), then you effectively make the first item of each type the player finds a waste ("Oh, so that's what that did. If only I had another one."), and if it's a bad item, the effect is not that different from a trap that the player merely has leeway towards when it goes off, unless he decides simply to never use-ID anything.

This isn't to steer you away from making games with it, but instead to suggest caution.  If you're going to put randomized item definitions in your game, here's some important questions to ask yourself:
  • Can you use the item without identifying it first? If not, then why require item identification at all? In principle it just makes players wait until town to get the thing identified, or to just throw away such items. You should be trying to increase the number of interesting decisions the player has to make. In Rogue, all items can be used, whether you know what they are or not, although the consequences might be dire. Make the player decide: use it and maybe get hit with a bad effect, or save it and maybe get killed when the right thing could have saved your life.
  • Are there any bad items that the player might find? If not, then there's not much reason not to wait for a tight spot before testing, on the off chance that it'll be a helpful thing. In Rogue, every item type has bad versions mixed in with the good ones.
  • Are sources of identification scarce and uncertain enough that the player may be seriously inconvenienced should he decide to wait until using instead of using right away? If not, then best play demands that the player always wait, and the purpose of identification is lost. In Rogue, the only means of definite identification besides use is identify scrolls, which are the most common scroll, but still random.

    Enough yet? We're just getting started!
  • Is the game hard enough that the player has to use unknown items once in awhile? If not, then he'd be foolish to take risks, and the items might as well not even be in the game. Some games are so easy that a skilled player might not have to use any items at all, unknown or known. In Rogue... well, the game is of legendary difficulty.
  • Are items sometimes not identified after use? If not, then it only takes finding a single example of each item to learn what it is. In Rogue, frequently items are not ID'd on use. Particularly rings are only ever identified with scrolls or careful observation, but other items that sometimes appear to do nothing on use might not be ID'd.
  • Does it matter much what order items are used in, or do item effects mean different things situationally? If not, then item effects start to look like a sequence of unrelated events, rather than something that builds on the rest of the game. We saw how Rogue does it in the play example: if you drink Raise Strength then Poison, the effect is different than if you drank Poison then Raise Strength. Same items, but different consequences depending on how the player uses them. Healing potions can provide either a large immediate benefit or a small permanent benefit, depending on how many hit points the player has then drank, and can also cure blindness, making them incredibly valuable before Blindness potions are known.

    Still a bit left....

  • Can bad items sometimes be put to positive use? If not, then it starts to look again like the random number generator is directly determining how well the player will do, as opposed to giving him an opportunity to use his skill to make the most of a situation. In Rogue: actually, most bad items don't have much in the way of alternative uses, although bad potions can be thrown at monsters to affect them sometimes.
  • Is it possible to identify things in ways other than use and Identify scrolls? If not, well it's not a huge thing; there aren't many items in Rogue that can be figured out without use or identification. (There is one though, and it's important!) But this is one of the best aspects of NetHack's item ID: serious thought has obviously gone into making many items discoverable without identification, and even if it seems a bit easy in some cases (wands are pretty easy once you know how), it's still pretty interesting, without requiring a player resort to such means, if he happens to be unspoiled or doesn't want to bother.
  • Are there enough items in the game, relative to the length of the game and item generation rate, that the player is reasonably sure not to find everything in one game? If not, then at the point where the player knows what all the items are, item ID becomes moot. This is particularly bad for in NetHack, where most stuff is known by midgame. In Rogue: players will typically find around 60% of possible item types in a winning game. (Note 1: NetHack's DevTeam actually took some controversial steps, according to some fans, to remedy this, by introducing the possibility for some items and monster attacks to unidentify items. Note 2: ToeJam's Randomizer item, mentioned in @Play 79, is one way around this, by giving players the possibility of accidentally scrambling the item definitions.)
That last bit, by the way, goes a bit against prevailing game design dogma, which says you don't need a lot of kinds of items so long as they all fulfill some role in the game. Well, that does make sense... maybe it'd be more accurate to say that it's an argument against excessive game length. The greater the proportion of things you can discover in one playthrough, the easier the game becomes. Of course some items should be more common than others, even to the point where they're very likely to show up. A good argument could be made that scrolls of identification are important enough that the player should probably always find a few, and of course food rations in a game with a strong food clock are important enough that even Rogue guarantees they turn up one level in three.

There's another reason for having more items in the game than could be generated each play, and that's variety. If you can't find, say, a Ring of Slow Digestion in your current game, you'll have to made do without, using the magic items that are otherwise generated to make up for it. One way to think about it: if everything can reasonably be found in one play, then the player can use whatever tools he likes the best, which gives him greater agency, which means he gets to play the way he wants, true, but also means once he's won once he's much less likely to want to play again after winning – there's little scope to vary the game on successive plays. If the player must instead adapt his playing style to the situation, then replayability is increased.

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This has all been a huge infodump, and I'm sorry if it's been fairly obscure for casual readers. And yet there's still a lot left to say! But that I'll save for later.

Rogue's random items are carefully selected so that each has a specific gameplay purpose, some way in which it either lessens the weight of difficulty or (for bad or obfuscatory items) increases it. NetHack's items show similar attention to detail, each item with a specific play purpose. And there's still the topic of the identifications system of the future: Rogue's ID system is based on descriptions, but what would a game be like in which you had to, say, discover the specific gravities of potions to identify them, or apply something like the Mohs hardness scale to gemstones, or figure out a magic language to read the titles of scrolls? Maybe items types should be harder to differentiate from each other, or more vaguely typed. Don't be too quick to decry these ideas! It's not as easy to tell what ideas are good or not except in hindsight, and even then, execution is everything.

A game in which item identification takes center stage would be harder compared to Rogue, all other things being equal. So, what if we relaxed the difficulty in some other way? Maybe make the food clock is a little more generous, or give the monsters a bit less variety. Maybe such a game should provide players a list of all the possible items in the game, in order to reduce the usefulness of spoilers and FAQs?

An idea that I personally quite like is including a lot more kinds of items than could possibly appear in a single play-through, reducing the availability percentage from Rogue's 60% to something more like 35-40%. What would the consequences of this be on the game? Individual items would have to have less subtle effects, perhaps, to make up for the fact that the player probably won't be able to find more than one. Or maybe the possible items could be selected randomly from a list before the game starts, and those items would be the only ones generated; that way, whatever you do find, you have a good chance of finding more than one of, but other things won't show up at all.

Some of these items seem interesting, but they all also have their negative aspects. This is because Rogue's item ID system is exceptionally well-balanced. It's difficult to usefully change it in a way that could unequivocally be seen as better. To me, that indicates genius game design. But it also makes Rogue ID system a tough act to follow… which may explain, ultimately, why so few other games have tried to follow it.

Appendix: Rogue's Magic Items (source, plus a couple of contributions)

These items are those found in common versions of Rogue. Some versions may differ, like by splitting up identify scrolls among different item types or not offering scrolls of vorpalize weapon, so this should not be taken as definitive.

Scrolls: Monster Confusion, Magic Mapping, Hold Monster, Enchant Armor, Identify, Scare Monster, Food Detection, Teleportation, Enchant Weapon, Remove Curse, Protect Armor, Vorpalize Weapon, Light, Gold Detection, Genocide, Create Monster (bad), Aggravate Monster (bad), Sleep (bad), Blank Paper (useless)

Potions: Healing, Extra Healing, Gain Strength, Restore Strength, Haste Self, Magic Detection, Monster Detection, Raise Level, Restore Strength, See Invisible, Levitation, Blindness (bad), Confusion (bad), Paralysis (bad), Poison (bad), Hallucination (bad), Thirst Quenching (useless)

Rings: Add Strength, Dexterity, Increase Damage, Maintain Armor, Protection, Regeneration, Searching, Slow Digestion, Stealth, Sustain Strength, Teleportation, Aggravate Monster (bad), Adornment (useless)

Wands/Staves: Light, Striking, Lightning, Fire, Cold, Magic Missile, Slow Monster, Teleport Away, Cancellation, Drain Life (often bad), Polymorph (often bad), Haste Monster (bad), Invisibility (bad), Teleport To (bad), Nothing (useless)

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@Notes:

Steam's roguelike sale, mentioned a couple of days ago at the Blogger @Play blog, continues until April 27.  If for no other reason it's a good time to get Spelunky and FTL for very little money, but there are a number of other interesting games offered too.  For a few more, follow that link right there.

It seems like this column took forever to write, and I'm still not entirely happy with it, but it's up now at least, remaining problems can be fixed later.  Because it took me nearly a month and a half to get up, I'm going to try to get the next one up fairly soon, maybe a review, maybe a review of one of those games in the Steam sale?  Hmmmm....