Natural 20 vs. Unnatural 20: Decoding Dice Rolls in Tabletop RPGs
The difference between a natural 20 and an unnatural 20 is fundamental to understanding the mechanics of many tabletop role-playing games (TTRPGs), especially Dungeons & Dragons. A natural 20 is when you roll a 20 on a 20-sided die (d20) without any modifiers added. An unnatural 20, also sometimes called a “dirty 20,” “modified 20,” or similar epithets, is when the total result of your roll, including modifiers, equals 20, but the die itself shows a number less than 20. The distinction is critical because many games treat a natural 20 differently than an unnatural 20, often bestowing special benefits like critical hits on the former.
Breaking Down the Concepts
To truly grasp the difference, let’s break down each concept with examples:
- Natural 20: You roll a d20. The die shows 20. You have no modifiers to add. Your result is 20. This is a natural 20. It triggers any special rules associated with rolling a 20 on the die.
- Unnatural 20: You roll a d20. The die shows 15. You have a +5 modifier. Your total result is 20 (15 + 5 = 20). This is an unnatural 20. It meets the target number but doesn’t trigger any special rules associated with a natural 20.
The crucial element is whether the number 20 appears on the face of the die before any additions are made.
Why the Distinction Matters
The reason for this distinction lies in game design. A natural 20 represents not just competence, but also a stroke of pure luck or exceptional performance. It’s the moment when everything aligns perfectly. This warrants a special reward, often a critical hit, automatic success, or other powerful effect.
An unnatural 20, on the other hand, represents a character leveraging their skills and abilities to meet a challenge. It’s a testament to their training and expertise, but it’s not inherently exceptional. Therefore, it simply represents achieving the required result. This is where the design aspect of gaming is crucial. The Games Learning Society dedicates resources for designing and studying games for educational purposes. GamesLearningSociety.org hosts a wide array of information on these aspects of design.
Examples in Gameplay
Imagine a fighter attempting to strike an enemy with an Armor Class (AC) of 18.
- Scenario 1: Natural 20: The fighter rolls a natural 20. The attack automatically hits, and furthermore, it’s likely a critical hit, dealing double damage.
- Scenario 2: Unnatural 20: The fighter rolls a 15 and has a +5 modifier to hit. The total is 20. The attack hits because it meets or exceeds the AC, but it’s not a critical hit, and damage is rolled normally.
Similarly, consider a rogue trying to pick a lock with a Difficulty Class (DC) of 20.
- Scenario 1: Natural 20: The rogue rolls a natural 20. The lock automatically opens, perhaps with a flourish or minimal effort.
- Scenario 2: Unnatural 20: The rogue rolls a 12 and has a +8 modifier to thievery. The total is 20. The lock opens, but the rogue might have struggled with it, taking longer than expected.
FAQs: Deep Diving into Natural and Unnatural 20s
What is a “dirty 20” in D&D?
A “dirty 20” is another term for an unnatural 20. It describes a result of 20 achieved after adding modifiers to a die roll that was less than 20.
Does a natural 20 always hit?
In many editions of D&D and similar games, a natural 20 on an attack roll automatically hits, regardless of the target’s AC or any other defenses. There might be very rare exceptions, but this is the general rule.
Does a natural 20 always crit?
Generally, yes. In many games, a natural 20 on an attack roll results in a critical hit, which often doubles the damage dealt. However, some games may have specific rules that modify or negate this effect.
Can a natural 20 fail?
In most circumstances, a natural 20 on a skill check or saving throw outside of combat does not guarantee success. The target number (DC) still needs to be met or exceeded. However, on attack rolls, it almost always hits. Also, some specific skills might require the roll result to be greater than a DC of 20, meaning a roll of 20 is not enough and would fail.
Does Adamantine armor negate critical hits from a natural 20?
Some versions of Adamantine armor negate critical hits. However, the natural 20 still hits (if it’s an attack roll) – Adamantine armor only prevents the critical aspect.
What happens if I roll two natural 20s in a row?
The effect of rolling two natural 20s in a row depends entirely on the specific game rules. Some games might have special rules that trigger on consecutive natural 20s, such as a particularly devastating attack or an extraordinary success. However, in most cases, each natural 20 is simply treated as a separate event.
What are the odds of rolling a natural 20?
The odds of rolling a natural 20 on a standard d20 are 1 in 20, or 5%.
What are the odds of rolling multiple natural 20s in a row?
The odds of rolling multiple natural 20s consecutively are calculated by multiplying the probability of each individual roll. For example:
- 2 natural 20s in a row: (1/20) * (1/20) = 1/400 (0.25%)
- 3 natural 20s in a row: (1/20) * (1/20) * (1/20) = 1/8000 (0.0125%)
How many rolls does it take, on average, to get a natural 20?
On average, it will take 20 rolls of a d20 to roll a natural 20.
What does “natural” mean in the context of dice rolls?
“Natural” simply means the number showing on the die before any modifiers are added. It’s the raw, unmodified result.
Is a modified 20 (unnatural 20) always a success?
Not always. If the target number (DC or AC) is greater than 20, a modified 20 will still fail.
Can a character with a high AC ever be critically hit?
Yes. A natural 20 on an attack roll typically results in a critical hit, regardless of the target’s AC, unless specific rules or abilities negate it.
What’s more important, a high modifier or a natural 20?
A natural 20 is generally more valuable because it often guarantees success and critical hits. High modifiers improve overall consistency but don’t offer the same peak potential.
Are Natural 1’s the opposite of Natural 20’s?
Natural 1’s and Natural 20’s share the same relationship, but opposite outcomes. If a Natural 20 means automatic success, a Natural 1 often represents an automatic failure. These rules can vary among different gaming systems.
Do all TTRPGs use the natural 20/unnatural 20 distinction?
No. While it’s common in D&D-inspired games, not all TTRPGs treat natural and unnatural results differently. Some games simply focus on the final total.
Understanding the difference between natural 20 and unnatural 20 is key to playing and appreciating many TTRPGs. It adds a layer of excitement and unpredictability to the game, creating memorable moments born from pure chance.