RULES SUMMARY
Eureka is a neo-noir modern fantasy TTRPG and is a throwback to the 90s era of gaming. While Dungeons and Dragons and high fantasy games dominate the market now, games like Vampire the Masquerade and Call of
Cthulhu were once just as popular. Eureka's design philosophy and principles hark back to that style with bell curve dice rolls and focus on feats (called Traits) as the main mechanisms for character generation.
The setting, too, is 90s in design with a heavy focus on violent, over the top monsters who are victimized by their dark needs, and lethal gunplay. The book is very mechanically dense, particularly for an
indie game, and is currently over six hundred pages. There are many subsystems, special rulings and rule variants that make summarizing them succintly tough but I'll do my best below.
If you already are familiar with the rules of the game or just want to get to the meat of my review, jump ahead to Rules Review. If you want to hear only about the game narrative, jump ahead to Game Identity.
The core resolution mechanic for everything (except combat) is rolling 2d6, adding character modifiers and then adding contextual modifiers. While there is not currently a robust section on NPC creation
and play, I assume that NPCs work similarly to PCs and will be writing under that assumption. Players (and the GM) only need to roll is something interesting would happen on a success AND a failure. If a roll
does not have these two states, it is considered either an automatic success or an automatic failure depending on the context and nature of the situation. There are three outcomes to a roll. The action fails,
the action partially succeeds / fails or the action succeeds. These measure the magnitude of success, not the consequences of it. A good roll does not absolve a PC of the consequences of their actions. Shooting
someone efficiently is still a crime and shooting them more efficiently may in fact cause it to be more of a crime, changing attempted murder into murder.
For the non-combat portions of the game, rolls are broadly separated into Investigative and Non-Investigative rolls. The meaningful difference between these is that most characters acquire Eureka points only
from Investigative rolls, regardless of whether or not they failed those rolls. Players in fact, get more Eureka points for failing rolls versus suceeding them. When a player has filled out their character's
Eureka bar, they can retroactively declare that a clue they failed to get (or another character with certain Traits) was actually not failed. They can do this directly by changing the result or by getting a clue
that fulfills a similar narrative role.
The resolution system and the investigation subsystem are simple compared to the combat rules. The combat rules take up a significant portion of the book and have a lot more detail than the investigation system.
While individual combat actions use the same resolution system as the rest of the game, the introduction of penetrative and superficial health along with armor and weapons ratings change the depth of the system
quite a lot. When combat begins, the character (whether player or non player) that started combat takes the first turn. Then, the characters closest to that character take their turns, expanding outwards until
the farthest person. Characters are free to attack, defend, duck, hide or take any action. When taking action, they roll 2D6, add character modifiers and then contextual modifiers. Then the action succeeds,
partially suceeds or fails as expected. So a player has their character attack a monster, they succeed on their roll and the monster takes damage. Where the complications lie in that damage depends heavily on
equipment. What weapon the attacker is holding, what armor (or natural armor) that the defender has, what position the characters are in and the environment they are in.
This is further complicated by special rolls, such as the Woo Roll (named after director John Woo). The Woo roll is a roll that players wielding firearms can undertake, which determines what their bullets hit,
similarly to the action gunplay of John Woo's films. There is also the reaction roll. A player can take a reaction if they succeed a Reflexes roll, adding yet another verb to combat. Knocking out, grappling,
disarming, shoving, throwing and firing inside vehicles also have their own rules or rule variants which are beyond the scope of this summary.
Characters in Eureka are built out of several building blocks. They have Skills, which are what your character is capable of and how good they are at it. Traits, which functionally similarly to "Feats" in
other games such as World of Darkness or Pathfinder. These are special skills that a character has and they can have three to six of them. They have a Truth, which is similar to a FATE Aspect in that it is
used to mechanically inform roleplaying decisions. They have Composure and Health, the former representing their mental stability and the latter their physical stability. They have Fears (called Tiers of Fear)
which represent how much Composure damage they take from psychologically damaging situations. Finally, they have a pseudo-class. Characters in Eureka can be Human, Mages (functionally Psychic Detectives) or
one of many kinds of monster.
The Composure system is the most robust of the investigation subsystems. Every character has Composure. This effectively functions as Sanity in other games. If they run out of it, they start to act erratically,
if they keep losing it after that, they will die. Composure can be lost from failing to sleep or eat or from encountering fearsome situations. How badly a character responds to a fearsome situation is determined
by their Tiers of Fear but the circumstances under which Composure is to be rolled are outlined well in the book. Getting into fights, seeing supernatural events, seeing death or gore and threats of arrest or
poverty are all times to roll Composure. Composure rolls use the same 2d6 situation as the rest but use the modifiers from the Tiers of Fear.
Monstrous characters in Eureka can not regain Composure through normal means. If they are able to eat or sleep at all, they receive limited benefits. What sustains them mentally is killing bystanders. This is
to be kept secret from the rest of the party. Inter-party character drama is supported and encouraged by the system. Players are not supposed to show each other their characters' sheets and are supposed to keep
secrets from one another. If a monstrous character is discovered, this character loses their benefits and the other characters must make Composure rolls.