To understand who the third person in the row is, we have to understand what the First and Second variables are.
The most fundamental integer present in most video games. Can you guess?
It’s right there, in the top left corner of the image above.
Health! yes, health or life or HP whatever it is called. It’s the variable which determines the lose state of the game; if it goes down to zero it’s game over. Hearts are it’s most popular graphic representation along with the color being red (abstraction of our red colored blood).
Certain games remove the hassle of the player moving their eyes to one part of the screen to look at their health (most popular is shooter games where tracking enemies is first priority) and instead opt for the screen becoming increasingly red/discolored to communicate they’re nearing death.
The second variable serves the purpose of the player to use it extensively. With little to no penalty even if the value falls low. It is expendable in nature (exceptions of horror games etc) if not has an easily acquirable/regenerative form. They do not determine the win/lose state of the game.
This includes your mana(magic meter) which doesnt take long to regenerate so you can continue throwing fireballs from your hands. Rage meters in games take this form too as they’re often a get-out-of-jail card for temporary duration of advantageous power with no repercussions.
In God of War (below), using neither Rage mode nor Runic attacks have any real penalties, just cooldowns before being able to use them again.
Of course shooter games have in this their own way, it’s called ammo.
The bullets for your firearms. The lead which you constantly pump into your morally-different enemies.
In the image below, the bottom right corner shows the ammo level.
So if at all you are questioning by now, Why isn’t this the Third variable?
It’s because it doens’t dictate a game’s identity.
The third variable is the game changer. Remove this variable and the game is NOT itself, it loses identity. All games do not use this, nor need to. But to implement it successfully, this often becomes the measurable core mechanic.
It is a clear communication for the win state of the game:
By this I do not mean the overall win state of the game, completing it.
The higher it’s value, the closer the player is at overcoming their moment to moment challenges. An advantage of having the variable visible to the player is that they can always understand when they’re at a disadvantage and how to gain the upper hand.
So how is a standard core mechanic different from a measurable one?
Simple, these have progression bars(or in some form) that is visible to the player on screen.
For example, a Devil May Cry player who gets a SSS (highest achievable) rank during combat knows that they are playing in the most intended way the game is meant to be played because their actions resulted in the highest rewarding gameplay.
Notice the ‘Smokin Sexy Style’ rank to the right in the image below.
Again, not every core mechanic needs to be measurable, it’s completely dependent on how your game works. An example is God of War where the chained blades form the core mechanic but it’s not really a measurable type.
Can you even imagine how these games would work as described below?
Devil May Cry without it’s Style meter.
Sekiro without it’s Posture meter.
Grand Theft Auto without it’s Wanted stars.
Dark Souls without it’s Stamina bar.
The Sims without it’s overhead Diamond.
Sekiro’s posture meter is positioned prefectly so the player can see it at all times. Health bars in this game takes a backseat, as constantly pressurizing the enemy to break their stance is the primary goal in combat.
An arcade racing game, Split/Second has it’s power play meter just below the car. Use it to cause destructive events in the race track. It’s the game’s selling point.
Crysis was termed a tactical shooter because of the opportunities the Nanosuit provided. The suit’s energy gives the player short bursts of inhuman abilities. Remove this, and it can easily be called another CoD rip off.
Below I have an example of how character identity is flawlessly incorporated into the first variable itself.
*I couldn’t have imagined it in any other manner which fits best.
The health bar (top left corner)is constantly regenerating every second.
What a cool way to show off Wolverine’s healing factor!
As much as the idea of crafting a unique core mechanic and how well the player latches on to it might be the most daunting task for any game developer, a visible novelty factor can communicate your design in a most straightforward manner.
Thank you :)