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Gesture-based spell system

Started by July 04, 2009 04:40 PM
11 comments, last by supageek 12 years, 9 months ago
I am currently building a gesture-based spellcasting interface, for the iPhone's touchscreen. The idea is that the game will provide online matchmaking, and connect two players together for a duel. A player draws one of more symbols on the touch screen to compose a spell, and then casts it with a two-fingered swipe across the screen. Preliminary gesture detection is complete, and the program can interpret a wide variety of symbols with some success (circle, pentangle, arrow, lightning, square, ...). My question is to do with designing the spell system - an area in which I have extremely limitted (read: zero) experience. The concept floating around in my head runs something like this:
Quote: - Each player starts with a fixed amount of health - Players can cast defensive spells (which remain in play for some duration), or - Offensive spells, which have an immediate effect - Spells are stacked symbols, each of which has some effect - Elemental symbols are aligned (something like Magick the Gathering colours) to define relative strength (Earth, Water, Fire, Lightning, Wind, ...) - Defensive spells increase in duration and durability by the dificulty of drawing (circle, pentangle, stacked circle and pentangle, ...) - Bonuses stack Some examples: - Player1 draws a circle, and fire 5 seconds of basic defence, +50% efficacy against water - Player2 draws a pentangle, water and lightning 8 seconds of medium defense, +65% efficacy against fire or earth - Player1 draws an arrow, and fire basic damage, +50% damage against water
However, I don't really have a sense of how to scale this concept up into a full duel. In particular, I don't want to make the symbols too numerous or complex, as this makes both recognition and player education dificult. Any suggestions are very welcome! I know that spell design is a large topic with tabletop games, so I would also be greatful if you can point me to any resources in this area [smile]

Tristam MacDonald. Ex-BigTech Software Engineer. Future farmer. [https://trist.am]

My uninformed/naive notions are:
  • try to have the gestures be evocative of the effects of the spells, so a whirlwind spell would involve a circular/spiral gesture;

  • use a combinatorial system, so that, for example, if "thunder" is a three-finger upward gesture and "lightning" is a zig-zag gesture, then "thunderstorm" is a three-fingered zig-zag gesture;

  • provide access to a spell book, so that a player can look up spells at any time, but probably incur a time penalty for doing so, or something.

I assume that there is some character progression in the game, so new spells become available over time. Having intermediate tutorials - every time the player levels up, for instance - would give an opportunity for both refreshing knowledge of previously unlocked spells as well as learning to execute new spells.


Good luck!
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A dungeon crawler RPG game called Arx Fatalis has a system where you have to draw the symbols of each spell. Spells are a combination of different runes, for example the healing spell used the runes vitae (meaning health) and mega (meaning increase).

Heres a video of it.



One of the problems is that the game doesn't always recognize the rune correctly. This is more apparent under stress. (like near the end of the video where the player is trying to cast a spell but has trouble under stress)

I like the system though, since it introduced magic as more than a point and click adding skill into the mix. It also balanced more powerful spells as they have to be drawn in combat, and more powerful spells usually have both more, and more complicated runes to draw.
There is also a Nintendo DS title based on the idea of gesture-based spell duels: Doodle Hex.
Quote: Original post by Metsan
There is also a Nintendo DS title based on the idea of gesture-based spell duels: Doodle Hex.
Quote: Original post by Larrius
A dungeon crawler RPG game called Arx Fatalis has a system where you have to draw the symbols of each spell. Spells are a combination of different runes, for example the healing spell used the runes vitae (meaning health) and mega (meaning increase). Heres a video of it.
Ah, excellent - good to see how these things have been done by others!
Quote: Original post by Oluseyi
My uninformed/naive notions are:
  • try to have the gestures be evocative of the effects of the spells, so a whirlwind spell would involve a circular/spiral gesture;

  • use a combinatorial system, so that, for example, if "thunder" is a three-finger upward gesture and "lightning" is a zig-zag gesture, then "thunderstorm" is a three-fingered zig-zag gesture;
I want to aim for something a little more structured - sorcery rather than magecraft, if you will. Spell casting is a process of construction, and single symbols shouldn't do much on their own.

This is primarily to help with recognition - complex gestures are much harder to deal with than simple drawings.
Quote:
  • provide access to a spell book, so that a player can look up spells at any time, but probably incur a time penalty for doing so, or something.

I assume that there is some character progression in the game, so new spells become available over time. Having intermediate tutorials - every time the player levels up, for instance - would give an opportunity for both refreshing knowledge of previously unlocked spells as well as learning to execute new spells.
Spellbook, certainly - though i would like an element of surprise in unusual combinations.

Can't quite figure out character progression. I mean, slowly gaining new symbols over time is probably best - based on duels fought, or something. However, I am going to have to define a set of symbols and interactions, so that added symbols can expand the range of meaning without unbalancing the whole system.

Tristam MacDonald. Ex-BigTech Software Engineer. Future farmer. [https://trist.am]

A couple random ideas/questions, which will hopefully provide some food for thought:

Can gestures interact with what's on-screen? For example, could you circle something on-screen to select it as the target for a spell? Are there other potential targets, besides just your opponents? In what kind of environments are these duels fought?

Does the ordering of the symbols matter, or do they just have to be there together?

Do you plan on having pre-defined spells which are the only ones that work, or do you want a system where practically any combination can do something, with the meaning being determined on the fly?

Defensive spells should last a little longer than 5 seconds if they are to be tactically useful. It should last at least long enough for the caster to draw a couple more spells without worrying too much about being killed.

Here's where leveling might come in. A higher-level player can cast more complicated spells, because they require more power to work. For example, for the uber-powerful attack spell, you would not only have to put together a sophisticated gesture sequence, which must be learned, your character would have to have enough strength to put it in motion. Also, the strength of the character affects how strong variable-strength attacks can be, and how long defensive spells last, giving you time to cast bigger spells...

You could also only allow certain symbols to be recognized based on the character's level, which is basically what you meant by "gaining symbols over time".

This idea sounds like a lot of fun. Good luck.
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Quote: Original post by theOcelot
Can gestures interact with what's on-screen? For example, could you circle something on-screen to select it as the target for a spell? Are there other potential targets, besides just your opponents? In what kind of environments are these duels fought?
My intention was to keep the environment sparse - basically a spellbook, in which you cast spells, and a log of events (i.e. spells cast and opponent spells cast). However, I am a little worried that this sparsity, when combined with the memorisation of spells will put the game out of the casual realm...
Quote: Does the ordering of the symbols matter, or do they just have to be there together?
Depends how many combinations turn out to be needed.
Quote: Do you plan on having pre-defined spells which are the only ones that work, or do you want a system where practically any combination can do something, with the meaning being determined on the fly?
The latter, preferably, but of course that is an order of magnitude more tricky to define.
Quote: Defensive spells should last a little longer than 5 seconds if they are to be tactically useful. It should last at least long enough for the caster to draw a couple more spells without worrying too much about being killed.
Ja, example was back of the napkin [smile]
Quote: Here's where leveling might come in. A higher-level player can cast more complicated spells, because they require more power to work. For example, for the uber-powerful attack spell, you would not only have to put together a sophisticated gesture sequence, which must be learned, your character would have to have enough strength to put it in motion. Also, the strength of the character affects how strong variable-strength attacks can be, and how long defensive spells last, giving you time to cast bigger spells...
That seems very sensible - I wasn't sure how to introduce levels without completely fragmenting the player base. If we increase the complexity of spells along with the levels, it might allow lower-level players to compete with higher-level.

Tristam MacDonald. Ex-BigTech Software Engineer. Future farmer. [https://trist.am]

Quote: Original post by swiftcoder
Quote: Original post by theOcelot
Can gestures interact with what's on-screen? For example, could you circle something on-screen to select it as the target for a spell? Are there other potential targets, besides just your opponents? In what kind of environments are these duels fought?
My intention was to keep the environment sparse - basically a spellbook, in which you cast spells, and a log of events (i.e. spells cast and opponent spells cast). However, I am a little worried that this sparsity, when combined with the memorisation of spells will put the game out of the casual realm...


Having richer environments would add a more interesting tactical aspect to a duel, by allowing players to use magic to manipulate the environment to their advantage.

I had another brainwave regarding leveling. A person could choose to allow their magical increased power to be more applicable to a certain element or other use. Basically, let them specialize. This came up in the context of environments, because it would be interesting if one player's specialty was better suited to things in the environment, like if someone who specialized in water-based spells was in a duel on a beach. Oh well, more brainfood, anyway.
The richness of any system is based on the richness of what it can effect.

For instance, in Magic: the Gathering, you don't only have "health" that can be effected by actions. There are many other aspects of the game that can be effected like: Lands, Enchantments, Creatures, Spells, The "Stack", the cards in the hands, the card in the deck, the cards that have been used, and so on.

This is what makes Magic the Gathering fun and successful (and even if you don't personally like it you have to admit that it is successful).

These things act as "handles" into the game world of MtG. As the players can only act through these handles, then the more of them you provide the more options the player has.

Now, in the basic game you described, the handles are: Defence type, Attack Type and Health. Not all that much.

What we should try to do is expand what "handles the players have.

What if you could cause their screen to shake? This could disrupt the casting of a spell or at least make it difficult to cast it properly or quickly, but player skill is still applicable rather than just imposing a timed delay or such.

What if spells could give secondary resources? What I means is that if spells took Manna to cast (and did damage to health), the spells might give "Fire Energy" that allows you to cast more advanced fire spells, or do more damage with them.

If the players could see these types of secondary resources (maybe through another spell) of the other player, then this can be used as a "Signalling" gameplay element. As Players built up these secondary resources, their opponent (through spying spells or whatever) could see this and work out what spells their opponent might be trying to cast.

Also, you could use it to bluff your opponent but building up some secondary resources that indicated that you are going to cast say a fire spell, but then when they put up fire protections, you quickly launch a water type spell. This is using "Signalling" in a "Bluff" manoeuvre and turns a game of chance (because you don't know what your opponent is going to cast) into one of skill (reading your opponent and assessing what they are likely to do).

What if you could hold spells in a buffer and cast them from the buffer? This could add in some more flexibility to a player's casting. You could make these cost something, so that keeping them in the buffer might act as a continuous drain of power, but would give the player the ability to quickly cast these with out disruption.

These could also have secondary effects too. Spells in the buffer might act as protection spells, counter spells, Giving secondary resources, etc. It also means that there is another handle which can be used by the players (and targeted by your opponent).

What if spells can change the battle field? If you allow spells to be used to change where the battle is taking place, or the environment of the battle and these environments have some effect on the spells being used, then this give yet another handle that players can use to effect the game and try to achieve victory.

What if spells can be used in combinations? Secondary effects and secondary resources is like what I mean here. Using a series of spells to generate secondary resources would allow you to cast spells that use those resources. Also secondary effects might stack in interesting ways, like a water secondary effect, might stack with a wind secondary effect to change the environment of the battle to one of a storm (and lightning and thunder spells do more damage), or some thing like that.



You need to understand the difference between "Complex" and "Complicated" systems. Complicated systems are systems with many individual parts that don't necessarily have much interaction. Complex systems are systems that don't necessarily have many parts, but the parts that it does have interact with one another in many different ways.

So to simplify: Complicated systems are systems where the numbers are in the parts. Complex systems are where the numbers are in the connections.

Complex systems tend to be more interesting to people than complicated systems. IN board games, there is a split in the styles of games. In American style game,s they tend to be complicated games, but use heavily themed settings. In European (German) style board game, these tend to be complex games with a few rules and part, but they have heavy interactions between those parts, they also tend to be lightly themes (almost as an afterthought).

Both styles of games have their advantages and disadvantages. American style games don't have much replayability value and tend to be mainly for family (the simple rules and heavy themes are easy for children to grasp). Euro style games are less easy for people to initially grasp (especially for children), but have heavy replayability and are usually highly strategic.

And of course, there are hybrids of these two styles.

Which direction you decide to go down (Complex or Complicated) will depend on the type of player you are wanting to attract. IF you want to attract players who like heavily themed games, but don't like to think much about strategies and such, then a Complicated game is the way to go. If however, you want a more competitive player, one who like to strategy in their play, then a Complex game is what you will need to look at.

I am currently building a gesture-based spellcasting interface, for the iPhone's touchscreen. The idea is that the game will provide online matchmaking, and connect two players together for a duel. A player draws one of more symbols on the touch screen to compose a spell, and then casts it with a two-fingered swipe across the screen.Preliminary gesture detection is complete, and the program can interpret a wide variety of symbols with some success (circle, pentangle, arrow, lightning, square, ...).My question is to do with designing the spell system - an area in which I have extremely limitted (read: zero) experience.The concept floating around in my head runs something like this:
Quote: - Each player starts with a fixed amount of health- Players can cast defensive spells (which remain in play for some duration), or- Offensive spells, which have an immediate effect- Spells are stacked symbols, each of which has some effect- Elemental symbols are aligned (something like Magick the Gathering colours) to define relative strength (Earth, Water, Fire, Lightning, Wind, ...)- Defensive spells increase in duration and durability by the dificulty of drawing (circle, pentangle, stacked circle and pentangle, ...)- Bonuses stackSome examples:- Player1 draws a circle, and fire 5 seconds of basic defence, +50% efficacy against water- Player2 draws a pentangle, water and lightning8 seconds of medium defense, +65% efficacy against fire or earth- Player1 draws an arrow, and firebasic damage, +50% damage against water

However, I don't really have a sense of how to scale this concept up into a full duel. In particular, I don't want to make the symbols too numerous or complex, as this makes both recognition and player education dificult.Any suggestions are very welcome! I know that spell design is a large topic with tabletop games, so I would also be greatful if you can point me to any resources in this area [smile]


The symbol based spellcasting you suggest reminds me of Digata Defenders.It was a cartton in which people threw dice with different symbols to cast magic.to create powerful spells you had to throw several dice of the same or different elements.Maybe if you refer their symbols,you might get some idea.Here's the link:
http://en.wikipedia.org/wiki/Di-Gata_Defenders

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