Skill Ceilings and Floors

Well, I have a night to update, and, people have been asking me when I plan to post - so I am posting now.

I have been at college, and occupied with other projects and commitments (hello, shuffling work shifts to not be when I am 2 hours away learning) - and so, well... hey.... I don't have to make excuses to you guys. >:[

Anyway, long story short, 2 articles tonight, this one, which is mainly definition, the other a more practical problem.

Player Controlled Units

Also, it has come to my attention that a very helpful term being used to describe a 'player controlled character or class' is a 'Player Controlled Unit' - a PCU for short. I plan to use this as I am sick of having to make the distinction. The term is also of great use because it can be used for any game I can think of, even ones where class and character don't work (such as in Space Invaders - where you don't identify with the unit (not a character), and it is not in a series of classes) - it can even be used to describe weapons. So, now you know what a Player Controlled Unit is.

On to the post.

Skill Ceilings and Floors

Skill ceilings and floors are terms given to the skill levels at which a player controlled unit is capped by the game mechanics. They are often mistakenly used to describe the effectiveness of a unit at various skill levels.

These terms are extremely... murky (in a word). They are poorly defined, and, are often used incorrectly - leading to somewhat of a double meaning.

I will try to clearly rectify this, but, I may fumble with my words a little and edit the post several times to make the point clearer.

On to the definitions!

Skill Ceilings

Skill Ceiling - This is the term for the maximum amount of skill that can be applied to a player controlled unit with regards to its technical limitations.

Similarly, you can say that it is the point at which an additional application of skill will yield no additional effectiveness due to the limitations imposed on the unit through the game mechanics.

If you play at the skill ceiling of a unit (you apply the maximum effective skill to it), the effectiveness reached is considered the absolute potential of the unit.

This is where I draw the distinction between the two 'definitions' of a Skill Ceiling.

If you play at the Skill Ceiling (skill cap) you reach the unit's absolute potential.

This does not saying anything about the effectiveness of the unit, aside from that its absolute potential has been reached. Even if the unit has a high skill ceiling, and you reach its absolute potential, it may still be ineffective - this is a problem, as the player is not being rewarded for his skill.

I repeat, reaching the unit's absolute potential does not actually definitely say anything about how effective it is in practice. This is where the definition problems arise.

An example of a high Skill Ceiling is in shooting games, where an accurate weapon compliments player skill greatly - and players are expected to become more accurate when aiming, and aim faster to reach the high skill ceiling. This is an impossible skill ceiling to reach however, as the rate at which a player can react to an enemy threat is limited to the slow human reaction time, when compared to a computer's reaction time - seen when a player uses an aimbot. In this situation, a skill ceiling is actually limited more by the human than the game mechanics put in place.

If you were to lower the accuracy of a weapon or give it a large damage falloff over range, you would lower the skill ceiling of a weapon, as now regardless of player skill, they cannot properly attack at longer ranges (which in the majority of games takes skill), and aim is less significant due to the lower accuracy (aim takes skill).

So how does this relate to game balance?

The main message here is that it doesn't define the unit's power. It affects balance of the unit on the skill vs. power issue (I will talk about this issue at another time), but saying that a unit has a high skill ceiling does not make it a powerful unit. You could have a weapon that takes massive amounts of skill to aim, but it can still shoot bullets that deal 1 damage.

It should be noted however, that when you discuss the overall balance of a unit, you will usually be discussing its absolute potential, rather than its potential at lower skill levels (you want to eliminate skill from the equation, which applying a skill ceiling does) - and so, Skill Ceilings also apply in this scenario.

Also, It is often ideal to try and balance all unit's potential at each skill level.

Skill Floors

Skill Floor - The skill floor is actually the opposite of the skill ceiling, it does not concern the application of a large amount of skill, but rather, a lower amount of skill. Due to the floorlessness of a realistic low skill setting (the lowest skill level is not inputting commands, but that's useless), Skill Floors are often directly tied to effectiveness when being discussed (they are useless to us otherwise).

Again, I will make the distinction between effectiveness and the meaning of a skill floor.

A Skill Floor is the application of the amount of skill yielded from the lowest amount of experience with the unit, game, or genre of game in question.

The reason why I mentioned experience was to eliminate the issues surrounding the floorlessness of low skill settings. Basically, we're talking about new players to the unit, game and genre.

Now, I will just get this out. There is no such thing as a high or low skill floor.

While the Skill Ceiling quantifies "How much skill can be applied", a Skill Floor is the opposite. "How much skill can't be applied" doesn't make any sense, nor does any other opposite trying to measure a valuable. You can graph a skill ceiling, you can't graph a skill floor (it's effectively 0 with our current definition).

So why would we bother talking about skill floors? We talk about a unit's effectiveness at its skill floor.

If a unit is highly effective at its skill floor, it is considered to be imbalanced with reference to skill (this is that thing that's coming later).

A unit that is considered ineffective at the skill floor is... well... normal. Nothing more needs to be said.

So remember:

There is no such thing as a high or low skill floor.

When discussing a unit's skill floor, you must mention its effectiveness at this skill floor.

Skill Curves

Using these measurements, we can make a Skill Curve (not to be confused with a Learning Curve or a Skill Aquisition Curve (used in RPGs to map when units get spells and such))

A Skill Curve is as such:

The vertical axis is Effectiveness (what we are measuring).

The horizontal axis is Skill Applied (what we are given).

The 'Skill Ceiling' is a constant value of applied skill, found at the maximum of the horizontal axis.

The 'Skill Floor' is a constant value of applied skill found at the minimum (0) of the horizontal axis.

In most situations, 0,0 is not a point on this curve, as even unskilled players are often at least a *little* effective with a difficult unit. If they weren't, there would likely be very little development in skill before a player gives up.

So we have:

Adding a typical Skill curve, we have

Note the X, that is what's known as:

Peak Skill - Peak skill is a common point found on Skill Curves that denotes a point at which the player will reach a point where any increase in skill results in a negligible gain in effectiveness. It's not a peak really, as the effectiveness doesn't turn downwards after this point (that would be dumb) - but that's just the term for it.

The Peak Skill doesn't really mean much when it comes to design and balance - though, as with all points on the Effectiveness vs. Skill Applied graph, it's ideal to have them all in similar places for all units in the game.

Conclusion

Anyway, that was possibly one of the toughest posts to write - due to the confusing nature of the terms, just remember:

Skill Floors and Ceilings are values in skill, not measures of effectiveness at their respective skill levels.

Thanks.