What follows is the Arkana Engine, a set of rules used to play all kinds of tabletop adventure games. The rules ahead are the bare minimum necessary to run a complete game, and are more than robust enough to support a mess of house rules, hacks, and calls on the fly without ever grinding to a halt. Every single aspect of the Arkana Engine can be expanded upon as the players see fit, to reflect any setting or situation the GM may throw at them.
The core of the Arkana Engine is the Arkana Key, a 3×3, nine-cell table that represents a character’s base capabilities. Any time the character interacts with the world they do so by combining an Act (verb) and an Area (noun) to make a Phrase (verb+noun). The three Acts on the Arkana are Enhance, Control, and Diminish, which are marked in the three rows of the table. The three Areas are Body, Mind, and Spirit, marked in the three columns. Thus there are nine potential Phrases a character can use to interact with the world.
Ultimately it is up to the GM to determine which Phrases represent each action. Broadly speaking Enhance is used to make something better, Control is used to guide and direct something, and Diminish is used to make something worse, while Body represents physical structure, Mind represents perception and communication, and Spirit represents energy and motivation.
Each cell on the Arkana where an Act and an Area intersect is marked with a value from 2 to 6, called a character’s Base Scores. Each Base Score signifies the average level of success that the character can achieve with the associated Phrase when using it to make a Check.
A character’s Base Scores start at, and may never permanently be lower than, 2. At character creation, the player may spend a number of points assigned by the GM , if any, and raise their individual Base Scores to meet the requirements of the game.
The average Base Score for each Area is marked at the top of the corresponding column. The Body value is a character’s Health Level and the Spirit value is their Mana Level, showing the two ways in which a character’s toughness and resolve are depleted by damage and stress. The character’s Mind value is their Focus Level, showing the reflex, wit, and willpower that keeps them in action.
When a character takes Damage each point lowers the character’s Focus Level until it reaches zero, then excess Damage points lower either the character’s Health Level or Mana Level. A character’s Focus Level recovers back to full from moment to moment, but recovering lost Health and Mana requires rest and recuperation.
If a character’s Health or Mana Level reaches zero then they are incapacitated and require immediate attention to recover. If they do not receive the required attention then they expire. Whether by death, dismemberment, madness, or cowardice, an expired character can no longer continue and retires from play.
Some sources of Damage might specifically be directed at a character’s Body and lower their Health Level, while others may be directed at their Spirit and lower their Mana Level. For the sake of the narrative it is often beneficial for an GM to allow a player to decide what kind of Damage they take once their Focus Level is depleted, along with a justification as to why. The simplest and fastest way to to do so is to say all Damage taken in Conflict or under normal circumstances is directed at the Body, while all Damage taken by using Spells is directed at the Spirit.
For less lethal games it is recommended to combine Health and Mana into a single Wound Level. Once the total Wound Level is depleted the character is incapacitated.
Kit represents the items a character uses to help with their Checks. Kit rating represents the type of Kit that a character has a knack for.
There are three types of Kit: Armor, Tools, and Weapons. The Rating for each can be either + (Gain), 0 (Neutral), or – (Loss). A character’s Kit Ratings modify any Checks they make using that type of Kit, at the GM’s discretion.
At character creation, the player must either raise the rating in one type of Kit to + and leave the rating of the other two at 0, or lower the rating in one type of Kit to – and raise the rating of the other two to +.
Equipment slots represent pieces of Kit that a character keeps immediately at hand. By default a character has five Equipment slots.
Pack slots represent pieces of Kit that a character has on their person but not equipped. By default a character has five Pack slots.
Pieces of Kit take up a number of equipment/pack slots equal to the number of hands the Kit would require to hold or use. A two-handed sword, for instance, fills two pack slots. Likewise, on any Check a character may only actively use one kit slot for each free hand.
To resolve a task, the Player declares what they are going to do and the GM determines which Phrase best represents the action, then the GM considers the difficulty of the task and sets a Target Score for success. The player references their Arkana to find the Phrase’s Base Score and rolls two standard six-sided dice.
The dice may land on Gains (die values 5 & 6), Neutral (values 3 & 4), or Losses (values 1 & 2). Each Gain raises the Base Score by one and each Loss lowers the Base Score by one. Neutral dice are ignored.
The final value after applying Gains and Losses to the Base Score is the Result Score. If the Result Score meets or exceeds the Target Score then the Check succeeds.
-If the player’s Result Score is only 1 below the Target Score then task should succeed, but with complications.
-If the Base Score meets or exceeds the Target Score without rolling, the GM may choose to consider the Base Score as the Result Score of the attempted Task. If the Task is critical to the narrative, the GM should request a Check regardless of Base Scores.
Any time one character Assists another character it is done using the Cause and Effect model, where the assisting character makes the Cause Check using a Phrase that best represents how they are providing assistance, then the acting character makes the Effect Check modified by the Gains from the Cause Check. The assisting character rolls a number of Dice equal to the Base Score in the Phrase they are using for their Cause Check, then notes the number of Gains. The acting character then makes their Effect Check as usual, adding the Gains from the assisting character’s Cause Check.
At the GM’s discretion more than one character might assist another when they make a Check. In these cases the acting character makes the Effect Check and each assisting character makes their own Cause Check. All Gains from each Cause Check are added to the Effect Check.
When giving non-magical assistance all Losses are ignored on Cause Checks.
Typically, a character cannot successfully attempt a Check if the Target Score is more than 2 Gains higher than their Base Score. In these cases an GM may allow the character to attempt a Spell, risking their own well-being to perform outside of their normal abilities.
Spells use the same Cause and Effect model as Assisting, though it can be understood that a character is making as Assist on their own Action. The Cause Check is an internal action the character takes in order to enhance the external action of their Effect Check. For example, a character may not be able to kick a door down with a Diminish Body, so they decide to Enhance Spirit on themselves to give it that extra gusto to break through, In this case Enhance Spirit is the Cause Check and Diminish Body is the Effect Check. Similarly, a character might use Enhance Body as their Cause Check to impose themselves on an opponent and bolster a Diminish Spirit Effect Check intended to intimidate them.
At the GM’s discretion a more complex Spell might have two or more Cause Checks that modify the Effect. For a complex example, an Enhance Energy Cause Check might summon a fireball, followed by a Control Energy Cause Check to direct the blast, finished with a Diminish Body Effect Check to blast an enemy with the fireball and do Damage.
To resolve a Spell the character first rolls a number of dice equal to the Base Score of the Cause Phrase and notes the Gains and Losses, then makes a normal Check for the Effect. Each Gain from the Cause Check is added to the Effect Check, along with any applicable Kit ratings.
Attempting a Spell causes 2 Damage to the character, plus one Damage for each Loss on the Cause Check. Once a character’s Focus is depleted damage caused by casting Spells is always applied to Mana. For Spells with multiple Cause Checks the character takes 2 Damage plus the Losses from each individual Cause Check.
In some cases one or more characters may Assist another with their Spell. In this case the acting character resolves their Spell as usual, while each assisting character takes 2 Damage plus one Damage for each Loss on their respective Cause Checks. Only the acting character makes the Effect Check, despite each assisting character taking the minimum 2 Damage cost of the Spell.
It is up to the GM to determine the nature of Spells and Spellcasting in their games, such as whether they represent the use of magic, technology, or heroic effort. They should decide what Spells are capable of and how much more difficult they are than a mundane task. To restrict achievable effects, the GM may choose to have individual Spells occupy Pack or Equipment slots, or be expended when used, either permanently or until the character rests. The GM is free to define individual Spells as broadly or narrowly as they see fit. Furthermore, it is encouraged for Mana to be defined, and even renamed, to fit the game the GM intends to run.
Conflict arises any time the player characters come under threat. Time is tracked from moment to moment as characters act and react to one another, with the lines of battle portrayed through their Positioning. Conflict always has two sides, the Players controlling their characters, or “PCs”, against the GM controlling the environment and non player characters, or “NPCs”. Rounds of Conflict are made up of two turns, Advantage first and Disadvantage last. A character recovers any spent Focus and Actions at the top of the round.
To begin Conflict a die is rolled, 4-6 gives the Players Advantage, 1-3 gives the Players Disadvantage. If one side is ambushing the other, then ambushing side is granted advantage.
After Initiative is determined each character will take their Position, choosing between Guard and Cover. Position represents the ever shifting front of Conflict, with Guard portraying the clashing front-line and Cover portraying the supportive rear-line. During Disputes and other non-combat forms of conflict the characters’ Position represents the proverbial spotlight, with Guard portraying the primary speakers or actors and Cover representing those currently on the sidelines in reserve.
Each round a character may use two Actions. Actions can be used to Defend, Maneuver, or Attack. Enhance Phrases are used to Defend, Control Phrases are used to Maneuver, and Diminish Phrases are used to Attack.
The Phrase used to complete each Action’s Check is determined by the GM. The Result Score determines how much temporary Focus is generated by Defending, Initiative generated by Maneuvering, or Damage dealt by Attacking.
Reactions are resolved the same way as Actions, but may only be performed in direct response to an Action taken by a character on the opposing side.
Characters in the same position may use an Action to make an Assist another player’s Action. Reactions may never be Assisted.
Defending is done by making an Enhance Phrase Check. The Result Score raises the character’s Focus Level, potentially exceeding the maximum. Each character begins every round back at their maximum Focus Level.
Armor Kit Rating is applied to the Result Score of any Defense Check using Enhance Body, once for each Equipment Slot occupied by Armor.
Maneuvers are made with a Control Check. The Result Score generates Initiative, tallied towards their side. Moving, dodging, and some other actions not used to attack or defend (as defined below) are resolved as Maneuvers. When dodging an Attack if the Result Score of the Maneuver exceeds the Base DS of the Attack then all Wounds are avoided, otherwise full damage is applied from the Attack.
Advancing from Cover to Guard or Retreating from Guard to Cover uses a single Maneuver. Passing Guard to approach an enemy in Cover uses a single Maneuver, which may be Reacted to once and Assisted by everyone on the opponent’s side. If the Maneuver Check to Pass Guard succeeds then the targeted opponent(s) are moved to Guard to represent the fight coming to them.
Tool Kit rating may be applied to Maneuvers if and only if the Tool in question is relevant for the task and occupies at least one Equipment slot.
Attacks are made with a Diminish Phrase Check. The Result Score is inflicted as Damage upon the target.
Weapon Kit Rating is applied to the Result Score of an Attack once for each hand occupied by a Weapon. “Close” weapons may Attack from Cover-to-Cover, “Reach” weapons may Attack from Cover-to-Guard or Guard-to-Cover, and “Ranged” weapons may Attack from Cover-to-Cover and Cover-to-Guard.
Narrative tasks in Conflict, such as unlocking a door, climbing a ledge, or Equipping/Packing kit, cost one Action. In these cases the Checks are made just like they would be out of Conflict, but provoke an Opponent’s Reaction.
Moving an item from Pack to Equipment or from Equipment to Pack costs one Action, though dropping an Equipped item always costs no Actions.
If a narrative task would provide an advantage in Conflict then it should be resolved as a Maneuver and generate Initiative accordingly.
At the end of the round any unused Actions are used as Maneuvers and rolled towards initiative. Once this is completed both sides tally their total Initiative and compare them, the winning side gains Advantage the following round. Initiative starts at 0 each round.
Spells in Conflict
When using a Spell in Conflict an Action is used for each Cause and Effect Check. The Effect is resolved as either Defend, Attack, or Maneuver Check and may be reacted to accordingly. These Checks are made sequentially, and a Spell may be split across multiple rounds so long as the flow from Cause to Effect is not interrupted by any other actions.
A character may choose to use both of their Actions to React with a Spell, in this case only one Cause Check may be used and both Actions are used at once. Characters may use an action to Assist another character’s Spell in Conflict, but not if it was cast as a reaction.
When appropriate the GM will allow the party to Rest, giving them a chance to recover from their wounds at a risk relative to their current situation. Once per rest players may recover either their Health Level with an Enhance Body Check or their Mana Level with an Enhance Spirit Check, recovering a number of Levels equal to their Result Score. Players may choose not to heal themselves, instead assisting in another character’s recovery.
The players and the GM should periodically agree upon goals for the party to accomplish, marking milestones in the party’s progress. Upon reaching a milestone the GM will award two to six Experience Points (XP) to each player.
XP can be spent to raise a Phrase Score at a cost equal to the current Score plus the next Score, thus to raise a Phrase Score from 2 to 3 a player would need to spend 5 XP, and to raise a Phrase from 3 to 4 it would cost 7 XP.
During play a character can spend an XP to add a single Gain to a Check before or after it is rolled.