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When is a Clone
by Raph Koster on 08/04/14 01:49:00 pm   Expert Blogs   Featured Blogs

The following blog post, unless otherwise noted, was written by a member of Gamasutra’s community.
The thoughts and opinions expressed are those of the writer and not Gamasutra or its parent company.


This was written in part in response to all the discussion around cloning going on in the game industry these days. As it happens, I read this Gamasutra blog post:

Everything that can be invented has been invented.

- Svyatoslav Torick

Which prompted me to post this here. "Game" here used in a strict formal sense, to save me from typing “ludic artifact” over and over again.


Most games can be described as rules (e.g., processes that are largely based on conditionals, limits, and actions) and sets of numeric values (number of an asset type, values for things, etc). You also have a variety of metaphors and presentation elements that are used to convey these: visuals, sounds, etc.

In general, if we see a game that has all the same rules and all the same scalars, but uses different presentation, we can consider that “a reskin.” It is exactly the same as a Lord of the Rings chess set or the like.

If a game has the same rules but different scalars, we can think of it as the same game simply presenting alternate problem spaces. For example, changing levels is changing scalars. Changing jump distance, etc. This is generally also a “clone” or “reskin.”

Pac-Man Note, a scalar going to zero, or a new scalar that therefore comes with a new rule (limit, mechanic, input and contingent rule) effectively creates what I would call a “variant.” Many games include variants within their rules, others are sometimes considered new games. Look at Poker.

Variant trees can get pretty complex, and pretty soon we end up referring to a “family” of games.

If it gets large enough, we call it “a genre.” A genre shares a common core set of mathematical problems but the rules around them can be so diverse that any given pairing of two members of the tree will find little commonality. Genres are really best seen through cluster analysis because they can bleed into one another.

So: new unique rule combinations create new games, which by definition create the original “variant” though there is nothing to vary from yet, which makes them the first member of a new family, and potentially the founder of a genre. But usually games are not invented ex nihilo.

You have do have some numeric rules that are almost like “global variables” – one of these is a scalar for “turn time.” Changing this one can very much create a “new game.” The same game construct with turns, phases, or real time will get called “a new game,” because turn time is a rule.

The easiest way to “invent a new game” as opposed to simply cloning something is to take a ludic artifact and change one significant rule.

Miner 2049er Not all rules are created equal. Some rules are very much peripheral – for example, an in-built exploration system (such as finding secrets) is effectively a braided-in minigame that happens in parallel to the “main game.” This is where atomic analysis is useful. Usually, you can see where minigames exist in parallel to a core game, and it’s usually obvious which is the core and which is the minigame, based on where resources flow.

Sometimes, rule changes like this (as in Poker) feed back into the core structure, and become a scalar instead, creating that sense of family. So adding a wild card is unquestionably a rule change, but these days “number of wild cards” or "face up cards" are actually scalars from 0 to n. Similarly, FPSes have developed variants like this (instagib, for example).

The commonest way to find a major variant is to add a dimension. Move from 1d to 2d to 3d to 4d, or back. This has been the evolution of shooters, of racers, etc. Adding time as a dimension is also a common tactic.

New graph types is a very common way to do it as well. Going from Bejeweled to Hexic introduces a new kind of mathematical relationship and topology, which results in new rules to handle it, which means a new game. Flip & Flop

So, the recipe for inventing a truly new game:

  • Identify a new mathematical model. This is often done by finding a new kind of scenario to model: human relationships (The Sims), gardening (Farm Town), etc.
  • Proffer a dimensional change on an existing ruleset, such as Tetris modifying the classic game of pentominoes by adding time and movement vector. Pac-Man and Miner 2049er and Flip & Flop are almost the same game (traverse every node on the graph). But the rule changes are major.
  • Explore alternate sorts of graph structures, such as Blokus to Blokus Trigon or Gemblo. Jumpman vs Miner 2049er is a good example here, or indeed any other “gather things” platformer; changing the graph of points that require visiting alters much.
  • Offer a replacement goal within an extant rule structure, which can force a major variant. A racing game versus a demolition derby sort of racing game is an example here.

That said, the folk process virtually demands that games be cloned, experimented on, reskinned, and otherwise evolved as machines. Look at the tafl family of games, for example, or Nine Men’s Morris. Arguably a game that does not get cloned can never become a family or genre.

On top of that, there are expressive qualities in the metaphor that afford enormous artistic scope. They don’t fall into the realm of “ludic artifact design” but rather into “experience design” (both subsets of “game design”), but they still advance the overall field. Half-Life is perhaps the quintessential example here.

Anyway, where that leaves us with clones… first off, they’re normal. Second, we as (ludic artifact) designers work in rulesets, and rulesets are conventionally not protected except by patents – so we could protect these constructs, we just usually don’t bother. Third, without a good way to talk about rulesets, we use rules of thumb to point at stuff and say “that’s a clone,” so it’s a great place where formal game analysis methods help our thinking.

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Christian Nutt
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Tangentially related, at which point did MOBAs go from Dota clones to a genre? Was it when League of Legends came out? Do the "failed" MOBA attempts matter in the context of this discussion, etc? Maybe more academic than useful, dunno! That's definitely a "new emerging genre" (well, now it's in the phase where it's approaching saturation and people are thinking of more minute variants to make their games stand out, concentrating more on nuances).

Raph Koster
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I think we rarely call something a genre when there are only two examples, so there more that show up, the more likely we start to think of it as a genre. And yeah, failed attempts count, I think! We still perceive the variations in them, whether or not they are commercially successful.

I think MOBAs probably have their genre kings, and its over. In terms of commercial growth, anyway. So to ue Dan Cook's genre lifecyle, I think they are probably at peak and facing decline.

Daniel Cook
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I find old (and admittedly vitriolic) forum posts like this one fascinating:

The short of is that MOBA was one of many terms used in the early days of DOTA1. Then Riot adopted it and began promoting. Whatever the other reasons, I suspect being able to describe your game as something other than a 'Dota clone' was helpful.

ARTS was a competing term promoted by Valve. (Linked article written by Christian!)

The genre kings fighting to own the name of the genre...really quite lovely.

I agree with Raph's point that the PC Moba genre has hit maturity and it will be difficult for new entrants. Honestly Valve snuck in like it did because it is Valve. I doubt many other companies could have managed that particular play.

Folks *are* still trying to crack the mobile nut though and despite some early entrants there's no evidence of a genre king there. Since it is a design problem, not a polish problem (screen size, session lengths) it may be a while. A comparable situation is the gap between the arrival of successful a PC FPS (Wolfenstein 3D, 1992) and a successful console FPS (Golden Eye, 1997) was 5 years. And arguably true genre kings didn't emerge in the console market until Halo in 2001.

Raph Koster
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I think mobile is a platform, not a genre. So I see multiple genre kings that have come and gone: Dragonvale, Candy Crush, Flappy Bird, Clash of Clans, and so on.

R. Hunter Gough
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I think Dan was talking about moba on mobile, not mobile in general.

Raph Koster
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Oh, doh.

Can't say I have seen ANY MOBAs pop to the top on mobile.

Tyler King
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I'm going to toss my name in the hat of people who think the moba genre has not yet fully matured. While I don't think there will be many more mega hits, at least one more will become super popular(Heroes of the Storm, Blizzard). Blizzard throwing their support with their game is only going to mainstream the genre even more. Then when you look at the numbers for the tournament prize pools, streaming support, and the free nature of the games I think it is only going to keep getting bigger... For now at least.

Kujel Selsuru
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Iteresting ideas thanks for sharing :)

Mutlu Isik
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Nice article, thanks for sharing!

It seems to me that the first point in your "recipe for inventing a truly new game" would make the biggest impact. In other words, games that "identify a new mathematical model" would be least likely to appear like a clone. Would you agree?

I'm also very curious about the distinction you're making between "ludic artifact design" vs. "experience design". Would you mind elaborating this point a bit further? What's the difference?

Thank you.

Raph Koster
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Unquestionably, new models are the biggest break from existing games and therefore seem like "new games." Though sometimes, existing models end up converging back to existing games, but only in hindsight.

As far as ludic artifact versus experience: a ludic artifact has NO representation. Meaning, no art, no sounds. It is a mathematical construct only. It is pure systems design. Anything that provides a representation is then experience design, and generally speaking draws from other media -- visual arts, film, music, storytelling, etc.

Needless to say, nothing exists in that pure a form. But it provides a good way for thinking about the ways in which different disciplines mutually support one another.

Mutlu Isik
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Thanks, that's very interesting. I'm glad you mentioned that "nothing exists in that pure a form". Some games are very minimalist in design, but they still include graphics, colors, sound FX, animations, etc. All that adds up to an overall experience, even if it's minimal in that regard.

So that means every game includes a certain degree of "experience design". Is there a correlation between this degree and clone-worthiness? In other words, less experience design means more likely to get cloned (or be called a clone)?

Raph Koster
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More experience design raises the competitive bar, making it less likely to be cloned. After all, the audience sees a great experience versus a bare bones one, and chooses the great version. The next clone then needs to trump that. The result is usually a graphics arms race.

That doesn't mean it was less *worthy* of being a clone, except perhaps in the crassly commercial sense.

Kevin Fishburne
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"Needless to say, nothing exists in that pure a form."

You could add a NIGHTMARE difficulty mode where the game would stop executing the render and audio loops. You'd have to close your eyes and sense the game state.

In all seriousness though, excellent and interesting writeup. I love being able to distill and quantify seemingly complex systems, and your insights help us to do that.

Luis Blondet
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I wouldn't mind if someone made clones of games I loved, like Loco Malito did with Ghosts & Goblins with his version Maldita Castilla.

Heralds of Chaos was an awesome strategy game that GaiaOnline let die slowly. Same with Disney's Treasure Planet: Battle at Procyon, you can play the game solo, but cannot connect to multiplayer anymore.

Yeah, some games deserve cloning or copying.

George Menhal III
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Great article. Good timing, too. I'm currently reading "A Theory of Fun for Game Design" on Safari Books and I'm finding tons of great insights there, as well. Definitely appreciate your work, Raph.

Svyatoslav Torick
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Thank you for the most sane commentary on something I tried to prove a normal thing.

Wonder if you'd care to comment other parts of mentioned blog entry.

Mark Nelson
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Great post. But I have to focus on the Flip and Flop screenshot... Ahhhh. Memories.

Raph Koster
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I always go back to the early 8 bit stuff for examples. :) It cuts away the cruft!

Curtiss Murphy
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Are there boundary cases? If I understand correctly, rather than 'clone', you're proposing: Reskin, Variant, Family, Genre. And also proposing that inventing a new game involves orthogonal design such as: an entirely new model; a dimensional change; alternate graph structures; or replacing a major rule.

With that in mind, the boundary cases might include an Augmented Reality version of the same game, which might make it a reskin, a variant, or an entirely new game, depending on the subtleties of the design. Another boundary case might include a mixed media version that has similar game-play, with drastic changes in video, audio, or other senses. For example, an audio-ONLY version of a cookie clicker (ie, no rendering at all) game could be a reskin, a variant, or an entirely new game, depending on the design.

I'll need time to grok the subtleties. These ideas are well thought out and practical. Thank you for sharing.

Raph Koster
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I suspect audio-only, or other such radical interface changes, introduce new rules and problems automatically. I mean, audio only adds a whole new game system in terms of recognizing audio signals. An AR version... it'd depend, but also seems likely.

But yes, I am sure there are boundary cases, and it'll depend on what someone considers a new rule, or whether the graph structure is really different enough. If you added diagonals to Pac-Man, that's a new graph structure, but it doesn't feel big enough compared to say Q*Bert, which has an alternate graph, introduces different movement schema, AND has the "paint over" problem once you get past the first couple of levels.

Julian Cram
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I'd like to say that "Everything that can be invented has been invented" is just a clone of "there is nothing new under the sun"... :P

Alexander Jhin
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Nice article. However, one bit of advice didn't seem to fit with the rest: "Identify a new mathematical mode". The rest of the suggestions seem to be building off old inspirations, but that one piece seems to be creating an all new inspiration.