How Power Impacts Gameplay
By: Yvens Serpa
Tags: Gaming, Game Development, Games, Game Economy, Game Design

Gun Ammo can be converted into Bullets (another resource) by shooting. If a Bullet hits a vehicle, it will drain its Health according to the Gun Force of the vehicle that shot the bullet. A player can reload, taking Reload Ammo time to generate ammo (the vehicle acts as a Source of its own ammo).

Speed is a resource that is not immediately connected to the economy but is highly related to the gameplay. Since the vehicles have to move to chase and evade each other, the Speed dictates how they position themselves. Their positioning is notably connected to the running and gunning mechanic.

In a more detailed economy graph, we could include other resources such as the distance between players and the chase and evade mechanisms. Besides, if players can outrun the projectiles, these uncertainties could be added, such as the bullet's velocity and even their dimensions.

Even if the economy is described in full detail (which is not likely to be an optimal strategy), it is clear that the main elements are directly connected to the power resources. On the other hand, it might be easier to find the power resources by drafting the game's economy and figuring out which resources are more closely related to the game's core.

For this initial version of the Run & Gun game, the mechanics do not change, and each player's power remains the same during the game session. Even when one player runs out of ammo, its power calculation remains unchanged since it is just a matter of time until it gets all of the ammo back. We could argue that the player's power was temporarily lowered, but for this analysis, this is negligible because its impact is already covered by the Reload Time.

Differently, other games offer upgrades, i.e., mechanisms that increase the player's power, temporarily or not. When it happens permanently, then power also becomes an integral part of the game's progression.

Power, Difficulty, and Progression

When power varies during a game session (or during the game's duration, such as in a campaign or adventure), the game elements need to adapt to the new value. Otherwise, the game's challenges and difficulties are likely to be perceived as trivial and even boring.

This power adjustment process, i.e., adjusting the power of the game's elements to match the player's, does not need to be fully adaptative or automatic. Many games, especially more classic entries, alter the power of the game's elements from level to level. As the player finishes a task, the next one is tougher, and the elements involved are harder to overcome.

Other, more modern games, such as Hellblade: Senua's Sacrifice, offer an automatic difficulty selection according to the player's progress. As the player ventures forth through the nordic hellish landscape, the game adapts automatically according to the player's skill and power, to (try to) maintain a level of stress and challenge manageable.

Concept art from Hellblade: Senua's Sacrifice. Source: Official Website.

The power adjustment process is directly related to the concepts of absolute difficulty and relative difficulty (Adams, E., 2014). Whereas absolute difficulty measures the difficulty of a challenge on itself by including factors such as player skill required and comparing it with other (easier) challenges of the same type, relative difficulty estimates the difficulty relative to the player's current power.

When the power does not change during the game session, the distinction between absolute and relative difficulty can be ignored (Adams, E., 2014), as is the case for the conceptual game Run & Gun.

Power Adjustment Process with Absolute Difficulty

For the sake of the analysis, let us assume that Run & Gun has a campaign single-player mode in which the player faces off against consecutive challenges to become the King of the Arena. If all vehicles have a standard initial power of 27 (as calculated previously), the initial challenges must either present a lower power value or match it equally.

For example, the first challenge could be defeating a Pontiac with stats V=5, F=1, A=1, S=5, T=60, and Power=13. The Pontiac's Power is almost half of a standard car's power. That should help new players get to know the game and learn the controls without any immediate threat or frustration.

However, by approaching the King of the Arena title, the player should face opponents with higher stats, promoting a more challenging experience. An end boss could be a Volkswagen Brasília, with the staggering status of V=30, F=5, A=3, S=10, T=10, and Power=54. That is, the end boss has twice the power of the standard vehicle power. A benefit of using this approach is that, if the challenge proves to be nearly impossible, we can resort to adjust the stats and compare the power values again.

Notice that in both cases, and all cases in between, the player's power does not change between combats. On the other hand, the player's experience and skill do. As more challenges are overcome, the players improve their own abilities, fighting better and mastering the game.

Comparison of Power through different Levels, with a fixed Standard Power. Source: Yvens Serpa.

With this numerical analysis, we can also plan the game's progression by plotting the power values. The chart above shows different approaches to power adjustment through the game's campaign. The dotted black-line, Standard Power, is just a guide marking where Power=27 is for comparison. These approaches are:

Linear: The power increases by the same value at every level. Non-Linear: The power increases non-linearly (multiplying it by a factor, for example) at every level. For the chart, every level multiplies the previous power value by 1.25 (the equivalent of increasing it by 25%). Steps: The power increases arbitrarily, including repeating the same power between levels, conforming to a certain design. For the chart, the power only increases after 2 consecutive levels. This approach is meant to help streamline the difficulty. Sawtooth: The power fluctuates (increase and decrease) while consistently increasing. This approach reduces the difficulty after each higher challenge. Notice that the power between levels is steeper, but the player can take a break after each jump due to the reduced difficulty of the following step. This approach is deemed to achieve a good pace over the course of a game (Adams, E., 2014).

The Steps and Sawtooth approaches are quite similar because they do not follow a standard mathematical equation. The biggest difference between the two is that the Steps approach never reduces the power; it either stays the same or increases, while the Sawtooth can either increase or decrease the power for the sake of achieving a good pace.

Power Adjustment Process with Relative Difficulty

The previous section discussed how the Power Adjustment Process could be numerically analyzed in a game with only absolute difficulty, i.e. when the player's power never changes during the game session. To study this process under relative difficulty, let us assume that now, in Run & Gun, the player gains a number of points to distribute between its stats after each level.

The number of points conceded can be analyzed under the same approaches as the game's progression seen in the previous section. The player can get more points linearly (increments of the same number), non-linearly (increments follow a non-linear formula), by steps (increments in different steps), or with a sawtooth pattern (increments in different steps that varies from higher and smaller values). The chart below shows a comparison between these approaches and the previous ones: