Sphere RPG System Mechanics

Costs

Most stats are bought on a sliding cost scale. The base cost to do so is as per the table below.

Level 1 - 1 CP - Hobbyist/Amateur
Level 2 - 3 CP - Trained
Level 3 - 6 CP - Professional
Level 4 - 10 CP - Expert
Level 5 - 15 CP - Master
Level 6 - 21 CP - Superlative

In short, the base cost to improve a stat costs (current level + 1). Depending on the stat being bought, this may be multiplied as follows.

Attributes have a x5 multiplier.
Characteristics have a multiplier of (4 + 1 for every additional specialization in the same attribute). Furthermore, Characteristics may not be higher than 1/2 (round down, min 1) of the parent attribute.
Skills are of several difficulties.

Simple Skills have a cost multiplier of x2.

Difficult Skills have a cost multiplier of x3.

Very Difficult Skills have a cost multiplier of x4. Very Difficult skills generally represent those that require substantial time committments - as an example, most science skills are Very Difficult as they require years of dedicated learning.

Attributes & Characteristics

These are the defining 'hard' characteristics of your character. Attributes are your dice pool to resolve tests. Characteristics are essentially 'sub-attributes' and are applied to specific tests, in which case they add dice as if they were attributes.

Physique

This is the raw physical prowess of your character while she is on her own two feet, governing everything from strength, agility, endurance, athleticism and general toughness.
Available characteristics for Physical are:

Dextrous

Big

Fit

Intellect

Your innate intelligence, as well as your ability to notice things and act on your feet.
Available characteristics for Intellect are:

Quick-Witted

Intelligent

Perceptive

Charisma

Charisma measures the likeability of your character in several ways. Although few player characters are anything but superior in physical attractiveness, those with high Charisma do tend to be the coolest or hottest, and they do tend to sell more figurines.
Available characteristics for Charisma are:

Forceful

Manipulative

Friendly

Skills

Skills are things your character has learned how to do. Swordsmanship, hyperspatial navigation, accounting, monster ranching; all are skills. Skills are broken into various groups, depending on what attribute or specialization they are controlled by.
Skills provide a negative difficulty modifier (ie, they make tests easier).
Skills are divided into three main groups determined by their usual attribute dependency.

Somatic

This includes things like marksmanship, fistfighting, track and field training and null-gravity movement. The parent attribute for Somatic skills is Physique.

Athletics

Brawl/Martial Arts

Melee

Firearms

Legerdemain

Stealth

Endurance

Zero-G

Drive

Pilot (D); rolls Physique + Quick-Witted; this skill covers conventional joystick-and-footpedal piloting schemes.

Gunnery (D); rolls Physique + Perceptive; this skill covers the use of weapons on mecha and fightercraft that require both a keen eye and twitch reflexes.

Mecha Fighting; this skill covers mecha-scale melee and unarmed.

Academic

This is intellectual skills, ranging from mundanities like mecha engineering or accounting and languages to exotica such as infometric theory and ancient history. Academic skills normally default to Intellect.

Awareness

Investigation

Academics (Field) (VD)

Bureaucracy

Computer (D); this skill deals with complex programming and infosecurity tasks.

Engineering (Field) (VD)

Medicine (D)

Strategy (D)

Tactics

Security; this skill deals with mundane security systems, both setting them up and avoiding them.

Artillery (D); this skill covers large fixed weapons that use computerized targeting systems, exemplified by the batteries on warships or heavyweight missiles.

Remote Operation (D); this skill covers the operation of remotely-piloted craft, ranging from recon drones to mobile dolls. The maximum skill level (Pilot, Gunnery) usable via remote operations is 2x the Remote Operations skill level. Remote Operation can also replace Pilot. The key roll here is Intellect + Quick Witted

Neural Interfacing (D); this skill acts similar to Remote Operation, except it covers mecha piloted via direct neural interfaces. The key roll here is Intellect + Perception

Electronic Warfare (D)

Helmsman (D)

Social

How to make friends, exude good impressions and sleep with that hot White Rose princess. Social skills will default to their parent attribute Charisma.

Red Tape

Intimidation

Interrogation

Subterfuge

Politics (VD)

Savoir-Faire

Command

Etiquette

Performance (Field) (VD)

Resolution Rules

Fundamentals

Dice pool size is equal to the appropriate Attribute + Characteristic, with every dice equal or exceeding the target number scoring one success. Having a suberbly-toned mind or body doesn't make up for lacking in critical skills.

The base difficulty for tests is 10, modified by skills as well as various situational penalties or bonuses. No difficulty may be lowered to lower than 3. Difficulties may go above 10, though for casual gameplay it is suggested that difficulties above 10 simply be treated automatic failures.

Note that positive modifiers increase the target number and are thus bad whereas negative modifiers decrease the target number and are thus good.

Typical modifiers

Very Difficult task: +4

Particularly Difficult task: +2

Easy task: -2

Very Easy/routine task: -4

Distraction: +1 to +3

Appropriate paraphernalia/equipment: -1 to -3

Rolling above 10
For those situations where the game calls for rolling difficulties above 10, use the following rule:
For every 10 rolled, re-roll the dice looking for 3+ if the target is 11, 5+ if it 12, so on.

Rule of 1s
A 1 on any dice eliminates one rolled success; a reduction to less than zero successes results in a fumble. Fumbles are generally disadvantageous in some form but should not be specifically punishing or lethal (unless it's a rather explicitely dangerous situation, like fumbling your Use Lightsaber or Tightrope Over Lava rolls). 1s may be rerolled only if there are no other failures.

Rule of 10
10s count as a success and allow for a re-roll, potentially get more successes.

Rule of Supremacy
If the roll exceeds the difficulty by at least 100%, (ie rolling an 8 when the difficulty is 4), you may opt to roll another dice as if you had rolled a 10. Rolling a Supreme 10 counts as two successes and allows for a re-rolls. Of course by this point you're probably already accumulated more than enough successes; GMs and players are encouraged to avoid this rule in the interest of fast play.

Damage and Survival

Hitting with a weapon requires at least one success; bare-handed attacks, melee weapons and ranged weapons with Precise add one dice to their damage roll for every additional success scored on the to-hit roll. Attempts to dodge, parry or otherwise avoid the attack eliminate successes on a 1:1 ratio.