1. d20 SPECIAL System

Rule Zero:

ExplorersBefore starting any discussion of the game system, one concept must be made clear. The most important rule in d20 SPECIAL is that all rules are servants of the game. This is such an important idea that it is considered ‘Rule Zero’. The rules of the game are designed to allow for an even playing field. They are a set of guidelines from which everyone can begin playing with one another in a consistent and mutually digestable manner. Check with your Game Master; he may have house rules or campaign standards that vary from the standard rules.

The rules are your servant, not your master!

Throughout the game, the GM and players must resolve whether or not specific actions succeed or fail. A character can try to do anything you can imagine, just as long as it fits the scene the Game Master describes. Depending on the situation, you might want to:

  • Listen at a door.
  • Access a computer.
  • Explore a location.
  • Bargain with a merchant.
  • Intimidate a raider.
  • Talk to a friend.
  • Drive a vehicle.
  • Activate an unknown relic.
  • Search for a clue.
  • Bluff a security bot.
  • Repair an Ancient device.
  • Leap across the gap between two buildings.
  • Duck behind a pile of rubble.
  • Attack an opponent.

d20 SPECIAL uses a single core mechanic to resolve all actions, keeping play fast and intuitive. This involves rolling a twenty-sided die (or ‘d20’) against a key Attribute to determine success or failure. This is called an ‘Attribute check’ and is a simple rule that underlies virtually the entirety of the game. The use of Attribute checks as the core game mechanic is referred to as the ‘SPECIAL system’ (since the first letter of each Attribute spells the word ‘SPECIAL’).

Whenever the GM or the rules require you to see if your character succeeds with a task (such as an attack, the use of a special ability, or an attempt to save yourself from harm), you do this:

  • The GM determines the key Attribute to associate with that activity.
  • The task is assigned a target Difficulty Class (or ‘DC’) that you need to beat in order to successfully perform the activity.
  • The player rolls a d20 and adds any relevant modifiers (such as for high or low Attribute scores, Prime bonus, mutations, character class, etc.).
  • The result is compared to the Difficulty Class. If the roll equals, or is higher than, the target DC, your character succeeds. Otherwise, he fails.

The most difficult portion of the check is determining an appropriate Difficulty Class. Much of the Game Master’s Guide is devoted to helping a new GM manage this.

Important: Not every action requires a die roll. Roll dice in combat an other dramatic situations when the success of an action is in doubt. Judicious use of the Attribute check is essential to maintaining the fast flow of action and adventure.

Types of Checks:

Different types of Attribute checks can come up during play, such as unopposed checks, opposed checks, saving throws, or attack rolls. While the rules for making these rolls follow the core mechanic, each type of roll has a slightly different purpose.

The DC for an Attribute check is set differently depending on whether the check is unopposed or opposed.

Unopposed Checks: An unopposed check’s success depends only on your character’s actions. The DC is set by the GM or the rules.

Example: You are trying to climb a dangling chain to scale some machinery in a ruined factory. The check depends only on the character’s Strength, training, and the roll of the die. The Strength check is compared to a target number set by the GM (probably DC 10). If the result is equal to or higher than the DC, the attempt succeeds.

Opposed Checks: An opposed check is used when another character actively attempts to prevent your character from succeeding at a given task. The DC is established by the check result of the character opposing your action. The opponent’s check might be made using the same Attribute you are using or a different Attribute, as defined by the GM or task description. The character with the higher result succeeds at the action being performed, while the character with the lower result fails. In case of a tie, the higher check modifier (including Prime bonus) wins. If these scores are the same, roll again to break the tie.

Example: You are trying to sneak past a guard. You make an Agility check opposed by the guard’s Perception check. If your result is higher, your character successfully hides, and the guard fails to spot him. If your result is lower, the guard spots you and your attempt to sneak fails.

Checks During Combat:

During combat, stricter rules apply to character actions. To remind you of this, different terminology is used. The Attribute check is referred to as an ‘attack roll’, and instead rolling against a target Difficulty Class, you attempt to roll higher than your opponent’s ‘Defense Class’.

To attack an opponent, roll a d20 and add your character’s attack bonus. If the result equals or exceeds the opponent’s Defense Class, the attack succeeds.

Important: There are two types of attacks in the game. A melee attack uses a weapon that attacks opponents in close quarters, such as a club, knife, or your fists. A ranged attack uses a weapon that attacks opponents at a distance, such as a bow or a grenade. Your character might have a different attack bonus for each type of attack.

On a successful attack, you roll to determine how much damage your attack deals to the opponent. Roll the type of dice indicated for the weapon used and add any modifiers that applies.

Damage reduces hit points. When all of a character’s hit points are gone, the character falls unconscious and is dying.


%d bloggers like this: