Eclipse Phase uses two ten-sided dice (each noted as a d10) for random rolls. In most cases, the rules will call for a percentile roll, noted as d100, meaning that you roll two ten-sided dice, choosing one to count first, and then read them as a result between 0 and 99 (with a roll of 00 counting as zero, not 100). The first die counts as the tens digit, and the second die counts as the ones digit. For example, you roll two ten-sided dice, one red and one black, calling out red first. The red one rolls a 1 and the black die rolls a 6, for a result of 16. Some sets of d10s, as shown above, are specifically marked for easier rolling and reading. Occasionally the rules will call for individual die rolls, with each individual ten-sided die listed as a d10. If the rules call for several dice to be rolled, it will be noted as 2d10, 3d10, and so on. When multiple ten-sided dice are rolled in these instances, the results are added together. For example, a 3d10 roll of 4, 6, and 7 counts as 17. On d10 rolls, a result of 0 is treated as a 10, not a zero. Most players of Eclipse Phase can get by with having two ten-sided dice, but it doesn’t hurt to have more on hand. These dice can be purchased at your friendly local game store or borrowed from another gamer.

Making Tests

In Eclipse Phase, your character is bound to find themself in adrenalin-pumping action scenes, high-stress social situations, lethal combats, spine-tingling investigations, and similar situations filled with drama, risk, and adventure. When your character is embroiled in these scenarios, you determine how well they do by making tests—rolling dice to determine if they succeed or fail, and to what degree.
You make tests in Eclipse Phase by rolling d100 and comparing the result to a target number. The target number is typically determined by one of your character’s skills (discussed below) and ranges between 1 and 98. If you roll less than or equal to the target number, you succeed. If you roll higher than the target number, you fail.
A roll of 00 is always considered a success. A roll of 99 is always a failure.
Jaqui’s character needs to make a skill test. Her skill is 55. Jaqui takes two ten-sided dice and rolls a 53—she succeeds! If she had rolled a 55, she still would have been successful, but any roll higher than that would have been a failure.

Target Numbers

As noted above, the target number for a d100 roll in Eclipse Phase is usually the skill rating. Occasionally, however, a different figure will be used. In some cases, an aptitude score is used, which makes for much harder tests as aptitude scores are usually well below 50. In other tests, the target number will be an aptitude rating x 2 or x 3 or two aptitudes added together. In these cases, the test description will note what rating(s) to use.

Difficulty and Modifiers

The measure of a test’s difficulty is reflected in its modifiers. Modifiers are adjustments made to the target number (not the roll), either raising or lowering it. A test of average difficulty will have no modifiers, whereas actions that are easier will have positive modifiers (raising the target number, making success more likely) and harder actions will have negative modifiers (lowering the target number, making success less likely). It is the gamemaster’s job to determine if a particular test is harder or easier than normal and to what degree (as illustrated on the Test Difficulty table) and to then apply the appropriate modifier. Other factors might also play a role in a test, applying additional modifiers aside from the test’s general level of difficulty. These factors include the environment, equipment (or lack thereof), and the health of the character, among other things. The character might be using superior tools, working in poor conditions, or even wounded, and each of these factors must be taken into account, applying additional modifiers to the target number and adjusting the likelihood of success or failure.
For simplicity, modifiers are applied in multiples of 10 and come in three levels of severity: Minor (+/–10), Moderate (+/–20), and Major (+/–30). Any number of modifiers may be applied, as the gamemaster deems appropriate, but the cumulative modifiers may not exceed + or – 60.
Jaqui is attempting to leap from one door to another across a large chamber in zero gravity. She’s in a hurry. If she misses the door, she’ll lose valuable time, so the gamemaster calls for a Freefall Skill Test. Jaqui’s Freefall skill is 46. Unfortunately the chamber is filled with floating debris that could get in her way. The gamemaster determines this is a Moderate modifier, reducing the target number by 20. Jaqui must roll a 26 or less to succeed.

Test Difficulty
Difficulty Level Modifier
Effortless +30
Simple +20
Easy +10
Average 0
Difficult -10
Challenging -20
Hard -30
Modifier Severity
Severity Modifier
Minor +/- 10
Moderate +/- 20
Major +/- 30

Sidebar: Simplifying Modifiers

Rather than looking up and accumulating a long list of modifiers for each action and doing the math, the gamemaster can instead choose to simply “eyeball” the situation and apply the modifier that best sums up the net effect. This method is quicker and allows for easier test resolution. One way to eyeball the situation is to simply apply the most severe modifier affecting the situation.
Example: Tyska is trying to escape from some thing that’s chasing him through a derelict habitat. The gamemaster calls for a Freerunning Test, but there are a number of modifying conditions: it’s dark, he’s running with a flashlight, and there’s debris everywhere. Tyska, however, has an entoptic map of the best route out of there to help him out. The gamemaster assesses the situation and decides the overall effect is that the test is challenging, and so a –20 modifier is applied.

Sidebar: Narrative Modifiers

If you wish to develop a more cinematic feel for your game, or if you simply wish to encourage your players to invest more detail and creativity into the storyline, you can award “narrative modifiers” to a character’s test when that player describes what the character is doing in exceptionally colorful, inventive, or dramatic detail. The better the detail, the better the modifier.
Example: Cole doesn’t just want his character to jump over the table, he wants to make an impact. Cole tells the gamemaster that his character kicks a chair out of the way, rolls over the dinner table on his shoulder, grabs a fork as he does it, makes sure to knock all of the fine china on the floor, then lands on his feet in a defensive martial arts posture, fork raised high. The gamemaster decides the extra description is worth +10 to his Freerunning Test.

Criticals: Rolling Doubles

Any time both dice come up with the same number—00, 11, 22, 33, 44, etc.—you have scored a critical success or critical failure, depending on whether your roll also beat your target number. 00 is always a critical success, whereas 99 is always a critical failure. Rolling doubles means that a little something extra happened with the outcome of the test, either positive or negative. Criticals have a very specific application in combat tests, but for all other purposes the gamemaster decides what exactly went wrong or right in a specific situation. Criticals can be used to amplify a success or failure: you finish with a flourish or fail so spectacularly that you remain the butt of jokes for weeks to come. They can also result in some sort of unexpected secondary effect: you repair the device and improve its performance; or you fail to shoot your enemy and hit an innocent bystander. Alternately, a critical can be used to give a boost (or a hindrance) to a follow-up action. For example, you not only spot a clue, but you immediately suspect it to be red herring; or you not only fail to strike the target, but your weapon breaks, leaving you defenseless. Gamemasters are encouraged to be inventive with their use of criticals and choose results that create comedy, drama, or tension.
Audrey is attempting to intimidate a low-level triad mook into giving her information. Unfortunately she rolls a 99—a critical failure. Not only does she fail to scare the guy, but she accidentally lets slip an important piece of information that she didn’t want the triad to know. If she rolled a 00 instead—a critical success—she would browbeat the man so thoroughly that he throws in some extra important information just so she’ll leave him alone in the future.

Defaulting: Untrained Skill Use

Certain tests may call for a character to use a skill they don’t have—a process called defaulting. In this case, the character instead uses the rating of the aptitude that is linked to the skill in question as the target number.
Not all skills may be defaulted; some of them are so complex or require such training than an unskilled character can’t hope to succeed. Skills that may not be defaulted on are noted on the Skill List and in the skill description.
In rare cases, a gamemaster might allow a character to default to another skill that also relates to a test. When allowed, defaulting to another skill incurs a –30 modifier.
Toljek is trying to casually sneak inside a hypercorp facility when he unexpectedly runs into a hypercorp employee. The woman he’s encountered doesn’t necessarily have grounds to be suspicious of Toljek’s presence, but the gamemaster calls for Toljek to make a Protocol Test to pass himself off as someone that belongs there. Unfortunately, Toljek doesn’t have that skill, so he must default to its linked aptitude, Savvy, instead. His Savvy score is only 18, so Toljek better hope he gets lucky.


If two or more characters join forces to tackle a test together, one of the characters must be chosen as the primary actor. This leading character will usually (but not always) be the one with the highest applicable skill. The primary acting character is the one who rolls the test, though they receive a +10 modifier for each additional character helping them out, up to a maximum +30 modifier. Note that helping characters do not necessarily need to know the skill being used if the gamemaster decides that they can follow the primary actor’s lead.
The robotic leg on Eva’s synthetic morph is badly damaged, so she needs to repair it. Max and Vic both sit down and help her out, giving her a +20 modifier (+10 for each helper) to her Hardware: Robotics Test.

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