Game Mechanics


This system was scrapped together from both Origins and Horizons systems, which has drawn inspiration from D&D 5e, FATE Core, and various other homebrew RP systems. Initially built by Cocoa, this system has been largely re-developed and improved on by the Millennium community, both through input and stress-testing.

Dice System

BrassCore2e makes use of ‘fudge dice’, or simply ‘df’ when rolling. When performing an action, you will be asked to roll four fudge dice plus the skill modifier (the value assigned to the skill you’re using). When rolling, it will generally be formatted as follows:


The outcomes of the die have potential to be positive, neutral, or negative, as indicated by a +, 0 or -.

Bob wants to attack an enemy with his combat knife. Bob has a 4 in melee, and would therefore roll the following:
He rolls 4df+4 and gets these results:
5 (4df+4=0, +, +, -)
Two die are positive, one is negative and one is neutral, giving a result of 5 (4+1). The neutral dice does not affect the score, and the minus dice cancels out the second positive dice.

If Bob’s resulting score is higher than the DC (Difficulty Class) the GM has set, Bob has landed a successful hit on the enemy. If not, he has missed.

Let’s say Bob has succeeded in passing the DC check. He would then roll a 2df, plus the melee modifier he used in his previous roll.
This roll will dictate how much damage Bob’s attack does.

Bob’s attack has landed successfully, and now must roll damage die. He would roll the following:
He rolls a 2df+4 and gets these results:
4 (2df+4=+, -)
One die is positive and the other is negative, giving a result of 4. The positive and negative cancel each other out, meaning the score is equal to the modifier provided, in this case.

Bob will have then dealt 4 points of damage to the enemy he has attacked.


Damage and Health

All player characters begin play with at least ten points of Physical Health (PHP) and Mental Health (MHP). PHP measures how much physical damage a character can take before fainting or dying, and MHP measures how much mental damage they can take before going catatonic or insane.

Physical health is 10+physical defence (PDEF).
Mental health is 10+mental defence (MDEF).

Countering Attacks:
When a character is targeted by an attack, that character's player generally has the choice of whether they want to defend with either Physical Defence or Acrobatics (but not both at once). If they roll greater than the attack roll, the attack misses or is blocked. In some cases, the GM might rule that you have to use one of those two rolls to counter an attack. For example, you might be able to take evasive maneuvers to try to avoid a tank shell, but no human could realistically survive a direct hit from one with no damage. Mental attacks are rarer, and are countered by Mental Defence.

Falling Unconscious:
If a character loses six PHP from one attack or four points of MHP, they fall unconscious until they receive proper treatment. Loss of mental health might also result in your character temporarily being out of your control.

Zero Health:
If a character has zero physical health, they die or are rendered seriously injured and unconscious by GM decision. If they have zero mental health then they are dead, rendered catatonic, insane, or mind controlled depending on context and by GM decision. Even if hitting 0 HP does not kill a character, it should have serious and lasting effects.

PHP and MHP are both restored by two points per in-game day, one of each at noon and midnight. In most games, any character with four or less PHP or MHP is confined to bedrest or an infirmary until they have recovered to five or more PHP and MHP. Additionally, any character who has more than five PHP and MHP but has suffered a devastating injury may be required to rest until healed, according to GM discretion. Characters who aren't in the infirmary but are under eight health in either category are advised to restrict themselves to lighter activities.

A Note About Medical:
Medical is rolled for medical knowledge up to the high-school or amateur, along with first aid. With GM approval, Medical can be rolled in place of Science in relevant situations. Also used for stabilizing wounds.

Beyond being useful as a knowledge roll, Medical can also be used to restore a character's hit points. Each character with ranks in Medical has a healing pool of Xd4 dice per run, where X is their base rank in Medical. A medic can use their turn to tend to the wounds of themself or another character, expending one of these dice and restoring hit points equal to the number rolled. Once the pool is out of dice, the character is out of healing.


Bob is at 10 PHP and takes 3 damage, going down to 7 PHP
Alice has 4d4 medical dice left in her pool
Alice heals John, rolling one of her medical die and getting a 2
Bob is now at 9 PHP
Alice now has 3d4 medical dice left in her pool

Minor injuries which do not deal real damage, as well as conditions such as bleeding, can be healed or made more stable by a medical roll against a DC set by the GM.

Only one healing die may be rolled in a turn, unless otherwise has been stated by the GM.


  • Physical Defence (Determines physical health, can be used to try to resist attacks and other sources of physical damage)
  • Mental Defence (Determines mental health, can be used to resist psychic illusions, attacks, and in some cases mind control)
  • Strength (Pushing, pulling, getting stuff open, holds)
  • Agility (Determines maneuverability and flexibility)
  • Perception (The ability to observe the world around you)
  • Melee (Attacking someone physically at close range)
  • Ranged (Used to shoot guns, throw grenades and other projectiles)
  • Stealth (Used for sneaking, pickpocketing and covert actions)
  • Academics (Used for history, knowledge on particular subjects, ‘book smarts’)
  • Science (Study of chemistry, mathematics, physics, biology, computer science, and other science fields)
  • Medical (First aid, healing, also dictated the healing die pool)
  • Engineering (Study, invention, and repair of mechanical devices)
  • Social (Used for lying, persuading, charming and intimidating your way through social situations)

Players have 33 points to spend upon character creation. Each point added to a skill is one less point in the total point pool. A maximum of 6 may be assigned to any one stat, and not all stats need to have a value. Physical Health and Mental Health do not deduct from this pool; attributes and skills do.

Specialty Skills

Some things are just not doable without training, years of experience, or a particular interest/knack for it. A skilled poet is not necessarily a skilled historian, even when both use Academics. You can't fix a nuclear reactor without a lot of training. You can't swordfight effectively just by being strong. This is where specialty skills come in: they represent the aspects of your character's background that make them unique.

There are two main types of specialty skills (there's really a lot more because people are unbelievably creative, but we'll focus on these two for now). The first is a specialty that provides a bonus to a certain action in certain conditions. This could, for example, be a bonus to shooting with a heavy weapon against a certain kind of target, or a bonus to knowledge rolls about reptiles (note that this could apply to either Science or Medicine rolls about reptiles, but because it's so situational you don't have to limit it to just one skill). The second, slightly rarer specialty skill is rolled on its own rather than boosting other rolls. This is usually done to accommodate for a certain skill that you think fits your character both thematically and mechanically, but for one reason or another was not covered in the main stats and skills. These talents are usually niche abilities, but can be incredibly useful utilities in the right hands. It's also worth noting that certain actions (such as repairing a nuclear reactor) can only be attempted by characters with ranks in the appropriate specialty skill, but that said specialty could be either of the two types above. It's advised that you work with the GM running your game and even other players to come up with specialty skills that will be useful and fun for your character without overshadowing other characters or derailing the plot.

You get 10 points to spend on the specialty skills of your choosing. The upper limit for spec ranks is 4 per spec. Be sure to describe the sorts of skills that each specialty encompasses, and your character's history should show how your character learned to do that.

On the whole, characters should probably not have base rolls of above 10 (the result of a rank 4 boosting specialty applying to a maximum ranked skill, and even then this should be rare) or below 0 barring truly exceptional circumstances.
Feel free to have some fun with your specialty skills, but don't go overboard.

Optional Rules

Gifted Characters

Gifts, magic, anomalies, superpowers. Whatever you call then, superhuman powers can add a certain dramatic flair to almost any setting. This is an optional rule that you elect to include in your campaign. Mechanically, all gifts must be listed as Specialty skills.

Since power has a price, any gifted character whose gift has more than two ranks gains a gifted flaw - some consequence of their nature that is a detriment to the character. It must limit them in some way when they're NOT trying to utilize their gifts - not being able to use one's abilities in the dark is not an adequate flaw.

Water-weaver 3. Alice is a talented aquamancer; she has the ability to control and manifest water. As a consequence of this, Hanna requires a very high intake of water, up to three times as much as a normal human. This requirement is higher in high-usage situations. She's also more vulnerable than others to taking damage from thirst in hot, arid climates as a result.

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