Player Core
Chapter 8: Playing The Game
Effects
Source Player Core pg. 418
Anything you do in the game has an effect. Many of these outcomes are easy to adjudicate during the game. If you tell the GM that you draw your laser pistol, no check is needed. Other times, the specific effect requires more detailed rules governing how your choice is resolved.
Many spells, magic items, and feats create specific effects, and your character will be subject to effects caused by monsters, hazards, the environment, and other characters.
Effects sometimes require checks, but not always. Casting a fly spell on yourself creates an effect that allows you to soar through the air, but casting the spell doesn't require a check. Conversely, using the Intimidate skill to Demoralize a foe does require a check, and your result on that check determines the effect's outcome.
Many spells, magic items, and feats create specific effects, and your character will be subject to effects caused by monsters, hazards, the environment, and other characters.
Effects sometimes require checks, but not always. Casting a fly spell on yourself creates an effect that allows you to soar through the air, but casting the spell doesn't require a check. Conversely, using the Intimidate skill to Demoralize a foe does require a check, and your result on that check determines the effect's outcome.
Duration
Source Player Core pg. 418
Most effects are discrete, creating an instantaneous effect when you let the GM know what actions you're going to use. Firing a gun, moving to a new space, or taking something out of your pack all resolve instantly. Other effects instead last for a certain duration. Once the duration has elapsed, the effect ends. The rules generally use the following conventions for durations, though spells have some special durations.
For an effect that lasts a number of rounds, the remaining duration decreases by 1 at the start of each turn of the creature that created the effect. Detrimental effects often last “until the end of the target's next turn” or “through” a number of their turns (such as “through the target's next 3 turns”), which means that the effect's duration decreases at the end of the creature's turn, rather than the start.
Instead of lasting a fixed number of rounds, a duration might end only when certain conditions are met (or cease to be true). If so, the effects last until those conditions are met.
Some effects can be ended early with the Dismiss action. An effect with the sustained duration lasts until the end of your next turn, but it can be extended as described in the Sustain action.
For an effect that lasts a number of rounds, the remaining duration decreases by 1 at the start of each turn of the creature that created the effect. Detrimental effects often last “until the end of the target's next turn” or “through” a number of their turns (such as “through the target's next 3 turns”), which means that the effect's duration decreases at the end of the creature's turn, rather than the start.
Instead of lasting a fixed number of rounds, a duration might end only when certain conditions are met (or cease to be true). If so, the effects last until those conditions are met.
Some effects can be ended early with the Dismiss action. An effect with the sustained duration lasts until the end of your next turn, but it can be extended as described in the Sustain action.
Range and Reach
Source Player Core pg. 418
Abilities that generate an effect typically work within a specified range or a reach. Most spells and abilities list a range—the maximum distance from the creature or object creating the effect in which the effect can occur.
Ranged and thrown weapons have a range increment. Attacks with such weapons work normally up to that range. Attacks against targets beyond that range take a –2 penalty, which worsens by 2 for every additional multiple of that range, to a maximum of a –10 penalty after five additional range increments. Attacks beyond this range are not possible. For example, using a semi-auto pistol, your attacks take no penalty against a target up to 60 feet away, a –2 penalty if a target is over 60 and up to 120 feet away, a –4 if they're over 120 and up to 180 feet away, and so on, up to a maximum of 360 feet.
Reach is how far you can physically reach with your body or a weapon. Melee Strikes rely on reach. Your reach is typically 5 feet, but weapons with the reach trait can extend this. Larger creatures can have greater reach; for instance, a crest-eater has a 10-foot reach. Unlike with measuring most distances, 10-foot reach can reach 2 squares diagonally. Reach greater than 10 feet is measured normally: 20-foot reach can reach 3 squares diagonally, 30-foot reach can reach 4, and so on.
Ranged and thrown weapons have a range increment. Attacks with such weapons work normally up to that range. Attacks against targets beyond that range take a –2 penalty, which worsens by 2 for every additional multiple of that range, to a maximum of a –10 penalty after five additional range increments. Attacks beyond this range are not possible. For example, using a semi-auto pistol, your attacks take no penalty against a target up to 60 feet away, a –2 penalty if a target is over 60 and up to 120 feet away, a –4 if they're over 120 and up to 180 feet away, and so on, up to a maximum of 360 feet.
Reach is how far you can physically reach with your body or a weapon. Melee Strikes rely on reach. Your reach is typically 5 feet, but weapons with the reach trait can extend this. Larger creatures can have greater reach; for instance, a crest-eater has a 10-foot reach. Unlike with measuring most distances, 10-foot reach can reach 2 squares diagonally. Reach greater than 10 feet is measured normally: 20-foot reach can reach 3 squares diagonally, 30-foot reach can reach 4, and so on.
Targets
Source Player Core pg. 418
Some effects require you to choose specific targets. Targeting can be difficult or impossible if your chosen creature is undetected by you, if the creature doesn't match restrictions on who you can target, or if some other ability prevents it from being targeted.
Some effects require a target to be willing. Only you can decide whether your PC is willing, and the GM decides whether an NPC is willing. Even if you or your character don't know what the effect is, such as if your character is unconscious, you still decide if you're willing.
Some effects target or require an ally, or otherwise refer to an ally. This must be someone on your side, often another PC, but it might be a bystander you're trying to protect. You don't count as your own ally. If it isn't clear, the GM decides who counts as an ally or an enemy.
Some effects require a target to be willing. Only you can decide whether your PC is willing, and the GM decides whether an NPC is willing. Even if you or your character don't know what the effect is, such as if your character is unconscious, you still decide if you're willing.
Some effects target or require an ally, or otherwise refer to an ally. This must be someone on your side, often another PC, but it might be a bystander you're trying to protect. You don't count as your own ally. If it isn't clear, the GM decides who counts as an ally or an enemy.
Areas
Source Player Core pg. 418
Some effects occupy an area of a specified shape and size. An area effect always has a point of origin and extends out from that point. There are four types of areas: bursts, cones, emanations, and lines. See Area for details.
Line of Effect
Source Player Core pg. 418
When creating an effect, you usually need an unblocked path to the target of a spell, the origin point of an effect's area, or the place where you create something with a spell or other ability. This is called a line of effect. You have line of effect unless a creature is entirely behind a solid physical barrier. Visibility doesn't matter for line of effect, nor do chain link fences and other barriers that aren't totally solid. Usually a 1-foot-square gap is enough to maintain a line of effect, though the GM makes the final call.
In an area effect, creatures or targets must have line of effect to the point of origin to be affected. If there's no line of effect between the origin of the area and the target, the effect doesn't apply to that target. For example, if there's a solid wall between the origin of a pocket vacuum and a creature that's within the burst radius, the wall blocks the effect—that creature is unaffected by the pocket vacuum and doesn't need to attempt a save against it. Likewise, any ongoing effects created by an ability with an area cease to affect anyone who moves outside of the line of effect.
In an area effect, creatures or targets must have line of effect to the point of origin to be affected. If there's no line of effect between the origin of the area and the target, the effect doesn't apply to that target. For example, if there's a solid wall between the origin of a pocket vacuum and a creature that's within the burst radius, the wall blocks the effect—that creature is unaffected by the pocket vacuum and doesn't need to attempt a save against it. Likewise, any ongoing effects created by an ability with an area cease to affect anyone who moves outside of the line of effect.
Line of Sight
Source Player Core pg. 419
Some effects require you to have line of sight to your target. As long as you can precisely sense the area (as described in Perception) and it isn't blocked by a solid barrier (as described in Cover), you have line of sight. An area of darkness prevents line of sight if you don't have darkvision, but metal gates and other obstacles that aren't totally solid don't. Usually a 1-foot-square gap is enough to maintain line of sight, though the GM makes the final call.