Gameplay Mechanics
The fast-paced mechanics of Astro Inferno are designed to be a midway between old-school simulation and modern storytelling. The system consists of checks made to your qualities and skills. The lower you roll, the better your result.
Checks
There is no specific turn order among players, just naturally build a great story together. Every time a character does something, that is an action. Whenever your character performs an action that could go wrong, you make a check, rolling a D20 and hoping the result is under your goal – your relevant skill or quality value.
If you roll equal to or less than your goal and no more than 16, you succeed, earning one story point [+] for each multiple of 5 below the goal. If you roll a 1, you perfect the check, doubling the story points [+] you earn and also awards you with a skill point. When rolling a perfect check, the 1 on the dice is regarded as 0, so a roll of 1 against a goal of 5 would reward you with 2 [+].
If your goal is 20, you succeed on a roll of 16 or less. If you roll 15 you earn one story point [+] (15+5 =20) on top of your success. An 8 would earn you two story points [+], a 5 would earn you three, and a 1, being a perfect roll, would earn you eight story points [+]! If you roll 19, 18, 17 or anything above your goal, you fail, with the GM determining how unsuccessful the action turned out to be, and also setting a negative aspect upon you or the world around you. This is always bad, and often demands you or the party to act in some way to get rid of the aspect. However, if you roll a 20, you botch the check, suffering a negative truth instead, but also earning you a skill point as a consolation.
Some modifiers may affect the result of a check, adding to or subtracting from it. Perfects and botches must be natural rolls, meaning they happen when the roll itself indicates 1 or 20, ignoring modifiers.
BOTCH - natural 20
High risk of not succeeding, receive a negative truth, earn 1 skill point.
FAILURE - above 16 or goal
Your action does not go as planned and has negative consequences.
Risk not succeeding, receive a negative aspect.
SUCCESS - below or equal to 16 or goal
You succeed and get what you wanted. Succeed, earn 1 [+] for every block of 5 below the goal.
PERFECT - natural 1
Succeed, earn 2 [+] for every block of 5 below the goal, earn 1 skill point.
Regard 1 as 0 when accounting for the blocks. Meaning if the goal is 5 a perfect check is regarded as two [+] 10 = four [+] and 15 = six [+].
Story Points
You earn story points [+] by rolling lower than your goal, and may use them in various ways, but only before new actions are taken – not counting those introduced by the [+] themselves, of course. In some situations, the GM may give suggestions, all in the name of a good story.
Tip
Spending [+]
Unless otherwise stated, [+] can be spent in the following ways. Aspect and truth cost can be increased by the GM depending on the scope.
Don’t let spending [+] slow down the game with tactical overthinking. It often makes for a better and more immersive experience to just go with the first thing you think of.
The Defiler is trying to hide from a group of cultists. She has a Sneak skill of 15 and rolls 5, so she succeeds in staying hidden and also gets 2 [+]. She decides to use one [+] to introduce that the cultists are “totally drunk” (an aspect), and the other [+] to successfully perform an extra Listen action in order to overhear some of their conversation.
The extra actions, aspects, and truths that you introduce using [+] don’t need to be directly connected to the action being checked, but must always be related to the context in which the action is happening. The GM has the final call on their approval, and may change them or discuss them with you to find something more suitable, always with the preservation of the narrative in mind.
It’s Your Story
Actions, aspects, and truths generally work best when they’re closely connected to the story and aren’t too powerful. These guidelines are highly subjective, though, since some groups enjoy stories with nonsensical or overpowered elements while others prefer to keep things very gritty and real. It is up to the group to discuss their expectations and thresholds, and this is something that can evolve over time. The campaign may begin feeling like a tactical military operation, and gradually grow to become a dark mythical odyssey, if that’s what the group is enjoying the most.
Check Modifiers
Straining Sanity
You can push yourself to improve your results in any check, but this strains your sanity [SAN] and awakens your inner demon. After rolling for the check, you may reduce the result by 5 (to a minimum of 1) and lose 1D6 [SAN] (or half as much, depending on your inner demon’s kink - see Satiating Demons). This can be repeated as many times as you want, as long as you have at least 1 [SAN].
Straining [SAN] can’t get you out of a botch or into a perfect, though – those have to be natural.
Offerings
The GM may spice things up by proposing an automatic fail on a check (already rolled for or not) in return for some kind of benefit. This is called an offering, and may involve experience points, stats – such as sanity [SAN], life [HP] or aura [AUR] – or whatever else the GM’s wicked mind comes up with.
Offerings can get stale quickly if overused, so the GM should use them sparingly, making each one feel like a special occasion.
Alternate Checks
Complex Tasks
Some objectives are too involved to accomplish with a single action, thus requiring complex tasks. In such a task, the GM or specific rules will designate a difficulty (as well as other possible conditions), which is the number of successes the party must collect from multiple checks related to it. Extra actions purchased with [+] from such checks may count as additional successes if they also relate to the complex task, and checks on repeated skills may be penalized by the GM if they feel the players should be a bit more creative.
If it is relevant, and the rules don’t state it, the GM decides how much time passes between each check, as well as the minimum number of checks that are required. Additionally, if you fail or botch during the process, the complex task’s requirements may be aggravated by the new negative aspects and truths.
Complex tasks can be treated as a narrative method between single actions and downtime, and is a great way to let the party perform longer tasks that otherwise could bog down the game.
Research
Investigating or studying something is often considered a complex task, which might provide not only story-related information, but also rewards like experience points or permanent improvements, such as quality, skill, or stat increases. Research rewards can only be collected the first time something is researched, and are split between the characters involved in the research in any way they choose.
The range of research possibilities is only constrained by the Game Master’s imagination, frequently manifesting in the form of tomes and artifacts detailed in the Satanic Journal.
It might sound like nonsense that something can’t be researched again by another character for them to get the rewards as well, but think of it this way – even when rewards are points and improvements, they still thematically represent information. And being such, there is always someone in the party who is the most knowledgeable at it, who, still thematically speaking, will naturally be the one to step forward when such knowledge is required, thus making it neglectable if others in the party are nearly as knowledgeable or not at all. In short – two people that know one thing each are better than a hundred that all know the very same thing, so go look for something else to research!
Panic Checks
Sometimes an action might be too hopeless, to the point that the GM simply determines that you cannot even attempt it. You can, however, ask to roll “impossible” actions as a panic check, in order to try something desperate or heroic. If the GM allows it, the check is rolled against the value of the goal divided by 5 (rounded down). Panic checks never provide [+], and all failures are resolved as botches but don’t provide any skill points. You can still strain your sanity to avoid failing, though, as long as you didn’t roll a natural 20.
The Thief is bound with chains by the servants of a Machine Angel. He tells the GM he wants to break the chains and try to catch a servant as a shield. The party laughs at this, but the GM reflects on it and tells the Thief that he could try a panic check for one of the Melee skills. The Thief has 16 in Melee Crushing, so he has to roll 3 or lower to succeed. Rolling any higher will botch the check, but knowing he can strain his sanity, he crosses his fingers and goes for it.
Aspects & Truths
In a world of Myth, Dream, and Creation the possibilities are endless. Reality changes on a whim, truths turn to lies, and if you just want it hard enough you can change the world itself.
Both aspects and truths are ways to introduce new elements into the ongoing narrative. Once introduced, the aspect or truth becomes part of the reality of the game world. The difference between them is that aspects expire, while truths are permanent, or at least very hard to change.
Please don’t begin an extensive list of each aspect or truth that gets introduced in the story, though. Instead, leave them as part of the narrative. And if some of them are forgotten, let them rest in peace in the void, remembering the following rule of thumb, if no one remembers, no one should care.
An aspect or truth that is either supernatural or universal has its base cost increased by 1 [+] (or 2 [+] if it is both). Anything that is highly unlikely in a given situation is considered supernatural, while anything that affects a large collective is considered universal.
| examples | |
|---|---|
| The door is “unlocked” | aspect [+] |
| the enemy is “suddenly feeling empathy for you” | supernatural aspect [+][+] |
| The city is “rainy” | universal aspect [+][+] |
| The sky is “darkened with an unexpected eclipse” | universal supernatural aspect [+][+][+] |
| The house is “made of stone” | truth [+][+][+] |
| supernatural truth [+][+][+][+] | |
| The population is “well educated” | universal truth [+][+][+][+] |
| The village is “built around a river of boiling acid” |
The costs of aspects and truths are not definitive in any way, and the GM is encouraged to improvise instead of trying to calculate the exact number of [+] needed.
Your sword is “on fire” because your empyreal master is enraged? Sure, it makes sense right now. This is technically supernatural, but whatever – that’s 1[+]
Affecting the Future and the Past
Aspects and truths are rarely just consequences of the action that led to their introduction. Much more than that, they have the potential to introduce brand new pre-existing elements of the story. Within the game world, these facts don’t begin to exist all of a sudden, but are instead considered to have been there the entire time.
A “tired” soldier has probably been tired all day. A “greedy” merchant has probably been greedy all his life.
Everything Is Aspects & Truths
Finally, checks and other mechanics aren’t the only way to introduce them. In fact, literally everything known about the game world counts as an aspect or truth – information introduced by the GM throughout the session, lore cited in this or other books as part of Astro Inferno’s mythos, and even consequences of player actions not formally introduced as an aspect or truth. And when in doubt, you can always ask.
Is the building made of stone? If the GM answers yes, that is a truth. The building is “made of stone.”
Impact on Gameplay
First of all, consider the narrative effect of aspects and truths – logical stuff that everyone agrees upon can affect gameplay without having specific mechanical effects. If a building is burning, it will probably burn to ashes, releasing a lot of smoke, lighting up everything around it, and so on.
As for the mechanical impact, before every check you roll, you may claim that one related aspect or truth is helping you with your action. If the GM approves your claim, you get one extra [+] on a success. Additionally, besides this first aspect or truth, you may also claim the aspect “assisted by…” for each of the other characters in the scene that, in previous actions, have done something specifically meant to assist you in your current action, getting another extra [+] for each of those.
Example Aspect use: The Defiler has rolled for Read Situation and realized the party is swarmed by adversaries. She also rolled a [+], which she wants to use as an extra action to assist The Thief with his machine gun. The Thief decides to open fire, claiming the aspect “assisted by The Defiler,” which contributes to the action and gets him an extra [+] if he succeeds. He may still make his own claim with a different aspect or truth, if there is one that helps with the action, thus getting him a total of 2 extra [+] if he succeeds.
The Gm Using Aspects & Truths
The GM may also affect your actions using aspects or truths. The usual way of doing this is by requiring a number of [+] to be spent. If the requirement of such a check isn’t met, it is considered a failure, and thus, doesn’t generate any [+] at all.
”Due to the wall’s darkness and slippery surface, you must roll 2 [+] to succeed in this Climb roll. If you only roll a success or 1 [+], the check will fail anyway.”
There are various other ways in which an action can be affected by aspects and truths, both positively and negatively. Moreover, they can also be used as passive effects that are not bound to any action. When evaluating how to do so, the GM should always keep in mind that, most of the time, sanity [SAN] is less impactful than life [HP], which is less impactful than aura [AUR],and story points [+] are somewhere in between. And of course, they should keep in mind what the aspect or truth is, since some things are naturally much more impactful than others.
- Since the tome is “cursed” you lose 3 [SAN] every time you interact with it
- Since the drink is “harvested from Freyr’s hair” you heal 5 ♥ if you drink it
- Since the city is ”boiling with unlight” you get 1 [AUR] for each day spent in it
- Since the food is “poisoned” anyone eating it will become “ill”
- Since you are ”huge” you don’t fit in the sewer tunnel at all. You simply cannot enter it
Finally, remember again that aspects and truths are much more than just sources of mechanical effects. They are an intrinsic part of the game world, which can have much greater impact in the story outside of checks, or even have no impact at all besides being a memorable quirk that everyone enjoys.