Core Mechanics

Worldlines uses a simple but flexible system designed to get out of the way of good storytelling while providing meaningful mechanical choices. The game is run by the Game Architect (GA) who provides the narrative basis and works as a quasi-referee to manage the game for the role players.

The Basics

When your character attempts something with an uncertain outcome, you roll dice and compare the result to a Task Difficulty (TD) set by the Game Architect. Meet or exceed the TD, and you succeed. Fall short, and you fail or succeed with complications.

Trait Dice

Every character has four Traits that represent their core capabilities:

• Combat — Physical prowess, reflexes, and battle-hardened resilience
• Wisdom — Awareness, intuition, and understanding of the world around you
• Intellect — Technical knowledge, reasoning ability, and academic learning
• Charisma — Social presence, emotional intelligence, and force of personality

Instead of static numbers, each Trait is represented by a die: d4, d6, d8, or d10. During character creation, you assign one die to each Trait. The larger the die, the better you are at tasks using that Trait.

Skills and Task Difficulty

Each Trait encompasses several Skills that represent specific areas of expertise:

Combat Skills: Weapons, Hand-to-Hand, Athletics, Evasion, Spirit

Wisdom Skills: Awareness, Stealth, Bushcraft, Insight, Investigation

Intellect Skills: Various academic, scientific, and technical specialties

Charisma Skills: Intimidation, Persuasion, Deception, Leadership, Performance

When you make a skill check, you roll the die associated with that skill's Trait and add any bonuses from training, equipment, or circumstances.

Task Difficulties

TD	Description
TD 4(3)	Routine task under normal conditions
TD 6(4)	Moderate challenge requiring focus
TD 8(5)	Difficult task under pressure
TD 10(6)	Complex challenge requiring expertise
TD 12(10)	Extreme difficulty, near the limits of possibility
TD 14+(12)	Seemingly impossible without exceptional circumstances

Throughout most of the game, the most common task difficulties should be TD 4-6, and occasionally TD 8. Task difficulties going 10 or higher should be reserved for special challenges that are narrative related, or make sense given the player making the check versus the task (e.g. a player with low intelligence, and no computing experience attempting to hack a data pad; in this case, the TD should be naturally higher than normal).

Task difficulties are designed to be adaptable to the players, their skillsets, the relative perceived difficulty of the task by the Game Architect. Keep in mind that partial successes are also possible.

Additionally, Worldlines does not abide by hard rules regarding success and failure. This means that a player skilled in specific traits may have an unlucky roll that does not meet the minimum TD roll assigned by the GA. Players will still succeed with lower roles but with consequences at the GA discretion. Typical partial success is defined by the value in parentheses above, with lower rolls resulting in harsher consequences paired with success.

Advantage and Disadvantage

Sometimes circumstances make a task easier or harder than normal. Rather than adding modifiers, Worldlines uses Advantage and Disadvantage:

Advantage: Roll your Trait die twice and take the higher result.

Disadvantage: Roll your Trait die twice and take the lower result.

Augmentation of Die Rolls

Augmentations allow another player to assist a skill check by lending their expertise, providing equipment or helping physically. An augmentation can only take place when the GA decides that it makes narrative sense. In these situations, the primary player still rolls their dice but also the die of the augmenter. The GA may then do one of two things depending on the situation:

• Take the better of the two results, or
• If permitted by the GA (on particularly hard tasks), you add both together for a stronger outcome.

The Flow of Play

Worldlines alternates between three modes of play:

Narrative Scenes focus on exploration, investigation, social interaction, and problem-solving. Time moves fluidly, and dice are called for only when outcomes are uncertain and meaningful.

Combat Encounters use the Momentum Phase system to handle fast-paced, tactical conflicts.

Downtime Phases allow characters to rest, train, craft equipment, pursue personal goals, and deal with the long-term consequences of their actions.