Game Design Analysis - Dungeons and Dragon's Concentration Mechanic

To begin, allow me to give a proper explanation of how Concentration works in DnD. I'll be talking about it in from a 5th Edition standpoint but older editions that have Concentration work much the same, the only real difference is that Concentration used to be a Skill where it is now just a Constitution Saving Throw (ergo, the heartier you are the more damage you can take while focusing on your spells).

Muscle Wizards are actually kind of a thing...

So imagine Concentration Spells as if they are tagged with a "Unique" modifier. What that means in game terms is that there can only be one instance of a Concentration spell at a time. So for example say you cast one spell that required Concentration, in order to cast another spell that had Concentration you'd have to cancel/abandon your first Concentration spell.

*Mana not always located in the knees*

If a player also takes damage while Concentrating on a spell then they must make a Constitution Save versus 10 or half the damage you take (whichever is higher). If they fail that save then they lose the spell they're concentrating on. That means if a player is flying high up and they take an arrow to the face they'd better hope they pass that save.

Avoid having this happen

There are some other cases that a DM might require a Constitution Save to maintain spells, however that depends on how 'hardcore' your specific DM wishes to play. Some may only call for it on receiving damage while others may call for it during any stressful/difficult situation, such as while riding on a crazy uncontrolled careening cart or during a oceanic adventure and your character is sea-sick.

---

Mechanical Analysis:
I believe this 'Unique' Concentration system was implemented due to the previous editions' buff mode. What I mean by that is previous editions didn't require Concentration for most buff spells (+AC, +Ability Score, etc) so most fights would start with the Wizard and Cleric buffing everyone to god status and fights would turn into a game of rocket tag (read as: everyone so crazy buffed that the first one to land an attack usually OH-KO's the other). Therefore Concentration was revised to make it so only one of the very useful buff/utility spells can be used at a time.
This change to Concentration makes it so casters can offer up a more unique answer to situations. Certain scenarios may call for Ability Score buffs or maybe something as simple as the ability to fly. With these scenarios smart players can feel like they always have an answer or a mechanic to add to the fight that will tilt things in their favor, but there-in also lies a drawback.

For Arcane casters they would have to go around and gather/memorize all these utility spells and for Divine casters they have to prep their spells ahead of time, so players may fight it difficult or annoying to plan for these situations unless the DM provides them with a pretty obvious clue about what's going to happen. The players have to be creative with the spells they have.
The other main drawback that many players express when looking at Concentration is that it seems too easy to break Concentration (hell, there's even a feat for doing exactly that called Mage Slayer). While I agree that is has become significantly easier to break Concentration, I think that it is a fair balance for casters. In previous editions past level 10 or so with straight casters (like Wizards) get incredibly strong, practically gods compared to the more martial way of fighting (ergo sharp/pointy/bludgeony things).

*Just a rough example, not a perfect demonstration*

Now, with Concentration, Wizards aren't these almighty figures and it brings them down to level with the other classes. They are still powerful but they have to play around certain opponents as well as planning out their spells and that makes combat actually interesting for casters. Instead of holding a person in place magically and flying off while peppering them with fireballs they have to choose between flying or locking them in place before raining the fire.... When talking about it like that it still seems powerful but I promise you it is better to add these limitations to prevent reality warping magic gods from running amok.

Lore Analysis:
In the end Concentration offers up a level of realism that would come with casting magic (I like to think that magic is similar to programming!). Imagine with me for a moment that you're a powerful Wizard and you wish to fly you and your allies up a cliff. Each turn you must mentally keep track of where your allies are in space so your spell can keep them aloft, as well as automatically moving everyone along with the world's rotation (lest your party suddenly become a Mach-1 bullet through the nearby village). That's a lot of math and variables to keep track of. So if you were up there in the sky doing advanced mathematics and some jerk blasts you in the chest with an arrow you may slip up with some of those numbers. And all of that example is just for the spell Fly.

As a DM it is a good exercise in imaginative thinking if you put yourself into the role of a Wizard and figure out why some of these spells have the Concentration tag attached to them. The answer could be as simple as applying an equal force in the exact opposite direction to the force being used in attempting to move (Hold Person); or as complex as stimulating every cell in another adventurer's body to induce a higher state of regeneration or enhancing the spine to increase reaction time and reflexes (Enhance Ability). Simple stuff, right?

Directional Hit Detection with Dot Products

Note: Before proceeding with this article, please make sure you have a basic understanding of Dot products as I will not be covering them in this post. That may be a topic for a future article. :)

To begin lets say that you have two objects; one doing the shooting and one being shot. We'll call them Gun (Shooting) and Enemy (Being Shot).

Since all of the math will be calculated around the Enemy we'll first need to get the Vector3 from the Enemy to the Gun, which can be done by taking the Enemy's position and subtracting the Gun's position (Enemy.position - Gun.position). We'll call this variable the Direction Vector

Next we'll have to calculate the Dot product of the Direction Vector around the the Enemy's Forward and Right Vectors. Doing so we can get some values which will help determine which 'quadrant' the Direction Vector is in, which can be used as a basic direction. For convenience I usually put these values into a Vector2, the X being the "Front-Back" value and the Y being the "Left-Right" value.

Now to explain what these numbers actually mean; you may have already guessed what they stand for because of my Front-Back-Left-Right names. So if the X (Front-Back) value is positive that means it is pointing in the same direction as the Enemy's forward, thus it is being hit from in front. And if it is negative then the Enemy is being hit from behind. Similarly, the Y (Left-Right) value works the same; with Right being positive and Left being negative.
Finally just compare the absolute value of the two values (X & Y) and the bigger value is the one that is closer to the point of impact on the Enemy.

Following this article should get you to detect collisions on the cardinal directions (Front, Back, Left & Right). However this can also be taken further to provide omni-directional detection by checking the corner cases. It should be noted that this method only works on 2D collisions, as there is no code to check for shots from above or shots from below (however is some cases those could be considered your Front-Back depending on the type of game being coded).
The following will be some example code; it should be noted that I am generalizing a Dot Product and Absolute Value functions so you'll have to make those yourselves, the first parameter for the Dot Function is the Vector we want to Dot towards and the second parameter is the Vector that we're getting from the Gun (the Direction Vector).

---

Vector3 directionVec = Enemy.Position - Gun.Position;

Vector2 dotVec = new Vector2(/*Front-Back Value*/Vec3Dot(Enemy.transform.forward, directionVec),

                                /*Left-Right Value*/Vec3Dot(Enemy.transform.right, directionVec));

//Front-Back value is greater than Left-Right value

if(AbsVal(dotVec.x) > AbsVal(dotVec.y))

{

//Front

if(dotVec.x > 0)

{

//Shot from the Front

}

      //Back

else

{

//Shot from the Back

}

}

//Left-Right value is greater than Front-Back

else

{

//Right

if(dotVec.y > 0)

{

//Shot from the Right

}

//Left

else

{

//Shot from the Left

}

}

Meeting Joe Barnes

Meeting someone so technologically focused like Joe was a great experience. Joe was, at the time, working as a Technical Director for Disney. He's been in the industry for 16 years, so Joe is a man with experience. He explained all of the various technical challenges he faced and gave us an important insight into what we might face if we're placed into a tech-oriented position.

He talked over what his forte or niche was, which to him was making the engine itself work. Joe liked to get down into the nitty-gritty parts of the engine and make all of the pieces fit together and work correctly. It was also a very big point to him that whenever code get's committed to a codebase it MUST be of the highest quality coding. That codebase is something that various other people may use and if it is not clean and concise in what it is doing, or if it is hard to use and easily confuses people, then it shouldn't be committed to the base.

Over his interview he also provided us with a few nifty tips that we should keep in mind when getting hired and working. So a few of the main points that Technical Directors look for when hiring is: strong proficiency in the language of that company's choice, an interest in the language so you're committed to it, knowing the ramifications of each line of code, being an excellent problem solver, and of course being a good team player. Being cocky and a know-it-all isn't going to help you impress the person hiring you. Also he explained how development kits are tricky to work with. Since development kits have extra memory built into them for debugging tools the line between how much memory a real system has vs how much memory a dev kit has is kind of hard to notice. Often times games leek over into that extra memory and when they start preparing to ship for launch the team will realize that the normal consoles now don't have enough memory. Joe also remarked how he doesn't actually find comments helpful in industry. While comments are usually a good idea in practice, it becomes inefficient in the actual workplace. Often comments are poorly done and even if they are well done they can quickly become obsolete the useless. Instead of documenting the entire process in comments, one should code their project in a simple and straightforward enough manner that anyone looking though it could piece together how it works.

How to: Breakable Models in Unity

Tools Required:

• 3D modelling software capable of exporting an .obj file
• Blender
• Unity

-----

To get started, make your object in the 3D modelling software of your choice (for this example I am using Maya).

Export that object to an OBJ file and import said file into Blender. In Blender one will need to go into the plugins and turn on Cell Fracturing. With that enabled there will now be a Cell Fracture button in the Objects Tool pane when selecting an object. We'll be using that tool to separate the model into tinier chunks that we'll be using as debris in Unity. Here's also where the trial and error comes in! Playing around with the setting and testing will be the best way to make a model that will shatter in the size and way you want. In the picture you'll be able to see my favored settings. Feel free to use those and see how it works with your model.

Then press 'okay' to allow the program to work through the model. Blender will begin splitting the model on the screen. Do not interact with it or close the program, just let it run its course. If the splits you decided to make aren't too small or plentiful then the model should be cut relatively quickly.

Now that we have a model with all of the broken up pieces we need we'll once again import the entire model as an FBX this time so we can use it in Unity. Once you have the FBX dragged and dropped into Unity we can start interacting with it in the engine.

Firstly, make sure the object's imported model has the Generate Colliders box checked. As the object is right now we don't have any of the necessary components on it to do our interactions, so we'll have to add them. First off, delete the Animator component of the object. It won't be needed for this tutorial. Next we'll need to add a RigidBody, Mesh Collider, Mesh Renderer and whatever other scripts we wish this object to hold. Once those are added, before proceeding, go into the Mesh Collider tab of the object and set it's mesh to the original model of the object. This model will have been included when you exported from Blender and will look like the object without being cut up. You can also freeze the constraints of the object, choose to use gravity or alter the mass of the object while we're here.

Now that we have the object created we need to affect it in the main script we have for running the level. Where the object is made in code, we'll also have to make an array of MeshColliders. This array will house all of the chunks we made via Blender and allow us to interact with each of them individually. However two extra items will be added to the front of the array that has to be dealt with. The first or [0]'th spot in our array is the model that is used as the object's collision. It is essentially an uncut version of the object. Unfortunately it is also visible so we'll need to turn it invisible so the chunk can be noticeably affected. To do this we'll call the [0]'th spot in our array and get the object's MeshRenderer before setting its 'enabled' boolean to false. By doing this we'll be turning off the rendering of the mesh, making it so we can still interact with the object just not see it. After that there's still one more object in our array that will mess with our functions. In the second or [1]'st spot of the array is the actual uncut base model of the object. It has been passed along between all of the editors and is just sitting in our array. We have to deal with it because otherwise our chunks automatically detect that they're colliding with it and explode outward. While impressive, it isn't helping us out.

So the best way to deal with this extra model is to just delete the [1]'s gameObject. Next, the best choice of action is to create a for loop that iterates over every chunk in our array. Inside this for loop we'll apply any alterations of the chunk's properties to all of the chunks. Firstly, we'll have to add rigidBodies to all of our chunks otherwise they won't interact with things as they should. As well, we need to set the MeshCollider component's 'convex' boolean to true for all of the children, thus allowing it to react to the chunk's specific model. I also recommend turning off gravity and freezing their constraints once more, just to be safe.

Now we'll need to make and add a script to the object that will be its manager when it is struck. To have the object detect when something has collided with it we'll use the OnCollisionEnter(Collision collision) method. This method automatically detects if another object is intersecting this one. So the first thing that has to happen in this code is that it has to detect that the object that is hitting it is the actual object that is supposed to hit it, instead of say something like the floor or character (unless of course you're planning for it to collide with those). So to detect this the object that is hitting has to have it's own manager. If it does, then we can use an if statement like such: if(collision.gameObject.GetComponent<ObjectManager>() != null). Doing that will check to determine if the colliding object has the ObjectManager we're expecting to collide with.

Now we can't just simply allow the object to react since the reaction it will do will be applied to the whole object instead of the chunks it collided with. We have to determine which chunks the colliding object will be reacting with. To do this we'll need to create a new array of Colliders and set that array equal to a Physics OverlapSphere. What this overlap sphere does is generate an invisible sphere on the colliding object which will detect all of the chunks that it is going to collide with. An example would look like such: Collider[] hitCollider = Physics.OverlapSphere([Here we pass in the position of our colliding object], [and here we pass in the scale or size of the OverlapSphere. I suggest using a value from 0.5 to 1, otherwise the sphere gets too large and starts making unnatural collisions]);

Now that we have all of the chunks we're colliding with we have to iterate over all of them and interact with the struck ones. We do this via another for loop of course! This time we'll iterate over the length of the Collider array we made. Inside the loop we'll use whatever physics or interactions we wish to apply to the hit chunks.

---

And that is how you create a breakable object and interact with its parts in Unity. Thank you for reading!

Meeting Ryan McBride

Ryan is a developer who has been with many of the large game companies in the Greater Salt Lake area, mainly being EA, Disney and SmartBomb. He talked a lot about his experiences getting into these places and the hiring process. He started off with a small explanation of who he is and how he started. He began in the QA department of a video game development studio. Over time he learned to code and then slowly transitioned into a developer position at the company he was at.

Next he explained a few of the difference between working at a smaller scale company versus and large company. He recommended that we all start with smaller game companies for jobs. Not only are they easier to get into but they'll also be using your skills in many different aspects. This shuffling around will give you experience in multiple places in game development and maybe help you find you niche. Then once you have suitable connection it is significantly easier to migrate to a larger scale game company. Often times companies look at your completed projects and contacts before even looking at any sort of education you may have, if checking that at all even. Then out of all of the types of video games he said that mobile was the easiest to get into currently since that market is expanding more than most, then later you can consider transitioning into PC or a console based company.

So Ryan explained to us a few good ways to impress companies. The first way he said to impress them was to pick up an open-source API and build something cool with it. By doing that we'd be getting experience working with code that is not ours and showing that we can take something pre-made and develop something neat using it. The next thing was to improve your Server managing skills since many things are moving to Cloud-based, that way you can 'wow' the companies by being prepared.

Ryan discuss that in his personal opinion these were his priorities when deciding if he should hire someone:

• People Skills and Communication come first because if you can't communicate effectively it will be hard to work with you.
• He then checks how their brain works. If someone is of a similar mindset then they'll be more open to your ideas and easier to work with.
• Finally he checks their experiences and education, more oriented towards their experiences. He explained that companies want to see that you can complete a project rather than leave many half-finished.

A few extra side notes he left us with were:

• That readable code will always be superior to compact code. Just because your code has less lines in it doesn't make it any more coder-friendly. The few milliseconds you shave off with the compact code slows down the overall development time because other coders will have to decipher what's happening, rather than having the code explain itself.
• And then he listed a few goo areas for developers to get jobs.
• San Francisco
• Seattle
• Austin

Meeting Shane Smit

When Shane Smit came in to present to us he covered a few new topics as well as going into depth on a few previously introduced topics.
Firstly he discussed his experiences in industry. Most of the time people will get tossed around to various areas of the industry to help out in multiple parts of the game, especially in smaller companies or as indie developers. So one should always be prepared to learn new concepts and be willing to learn. The industry is also heavily driven by money. This should sound like common sense but people underestimate just how important it is that video games make a profit. Every time a company agrees to make a game they, usually, have to invest large sums of money. A quote from Shane touched on this topic: "Video games are a service." Now that means that we, as developers, must make sure our games fit as a service and give the users something they're looking for. That means we have to adapt to what is currently popular with our audiences.

Shane went on to discuss how we have to make a game successful based on popularity. As previously stated, we must adapt to the constant changes of the market to make sure our games are relevant to what the consumer wants. One way of doing this is by developing games after popular movies. The hard part about making movies into video games is that they both have to be released at the same time, to capitalize on the market's hype. If they aren't released at the same time the game might suffer because the movie will lose some of its hype and become less popular. So crunch time is very important for these types of games. If the game isn't released by its expected date then the company is already losing a large sum of money.

Finally he discussed how games have to come together as a whole. To make a game successful it must be solid and complete. Now that might sound like common sense too but there are many games that are 'complete' but not 'solid'. To have a solid game aspects of the game cannot be missing or lacking. If UI or sound is missing or terrible quality people won't play it because of the general unpleasantness of it. One big aspect of the game that draws people in is the menu. The menu has to be appealing and cool to make people want to play and proves that your game isn't just a crappy student project. So making the game is actually a very small part of the designing process, with a majority of it spent making tools and making those tools work with the game.

Meeting Victor Chelaru

In our meeting with Victor he explained some of the process behind creating a game and the pipeline of people it goes through. He drew a diagram how a common pipeline would work: it starts at the developer who makes the concept for the game, then the developer passes it off to two teams; the artists and the programmers. The artists then draw up all the graphics that might be implemented in the game before passing those assets onto the programmers as well. The programmers then have to take all of this and make it into a workable game which is then sent off to marketing to promote. The problem with this way of doing this is that there has to be a constant dialog between the programmers and the artists / developer. And each dialog that has data loss, ergo some of the idea is lost from the developers original idea to what the programmer completes. Victor estimated that about 10% of the information was lost each step, so by the time it got to the programmers it could be as low as 50% of the original information that was intended to be passed along.

A fix for this, that Victor proceeded to speak about, was cutting out the middle man. Ergo he said that the developer should be as much of a programmer as possible, therefore negating the information loss. By doing this the game's core concepts are all there. As for the artists he explained how they should have an easy enough time implementing their assets into the game so they can see how it works and fix it as needed, thus removing the dialog between the programmer and the artist as well. Now this is the best case situation and it may be hard at times to even come close to achieving a pipeline such as this.

To finish he spoke about our goals and how we need to focus on what we truly need. As programmers & developers, we shouldn't try and expect what to do way ahead of time. If we try to predict everything we'll never actually get anywhere with coding it, we'll be stuck in the theory stage. Also the best feedback is from those who aren't developers or programmers, and who aren't afraid to hurt your feelings.