Status effects
Status effects are temporary, usually negative, character modifications resulting from the character's interactions with the game, such as poisoning after getting hit by a radscorpion, or addiction after consuming a drug.
For a list of effects associated with critical hits, see critical effects.
Contents
Irradiation
| Severity | Penalty |
|---|---|
| 5% | -10 healing rate |
| 10% | -5 Sequence |
| 15% | -1 Charisma |
| 20% | -1 Endurance |
| 25% | -1 Agility |
| 30% | -1 Perception |
| 35% | -1 Strength |
| 40% | -10% critical chance |
| 45% | -1 to all SPECIAL attributes |
| 50% | -3% to all damage resistances |
| 55% | -3 to all damage thresholds |
| 60% | -2% to all damage resistances (stacks for a total of -5%) |
| 65% | -1 to all SPECIAL attributes (stacks for a total of -2) |
| 70% | Maximum hit points reduced by at least 25% |
| 75% | Critical chance set to 1% |
| 80% | Healing rate set to 0 |
| 85% | Action points reduced by at least 50% |
| 90% | -1 to all SPECIAL attributes (stacks for a total of -3) |
| 95% | All damage resistances set to 0 |
| 100% | Hit points set to 1 |
Irradiation means radiation exposure.
Radioactive contamination builds up over time as you visit places with intense background radiation (such as the Glow or the Lost Hill bunker), get hit by attacks that expose you to radioactive particles (ELECTRO-RAD Rockets, Rad Shot, Aliens), or ingest radioactive substances. A status indicator will appear in the top‑left corner of the screen once there's enough radiation in you that it starts affecting your stats; mouse over it for details.
Any character can instantly become fully shielded from all radiation by equipping a suit of TMA Metal Armor. Failing that, the effects of radiation exposure can be mitigated by increasing your radiation resistance.
Radiation resistance reduces the dose of radiation you receive upon exposure by a percentage. It is governed by Endurance, which grants +2% radiation resistance per point (or 1% if you have Fast Metabolism).
Rad Resistance and Snakeater support perks grant 30% and 20% of radiation resistance respectively.
Rad-X grants +50% radiation resistance and increases its cap by 10%, allowing the stat to reach 100% (full immunity) but note that some types of radiation (such as that you get exposed to in the Lost Hill bunker) will penetrate a portion of your radiation resistance.
Characters overexposed to radiation suffer radiation sickness which leads to escalating penalties as radiation exposure continues.
The severity of your radiation sickness is displayed as a percentage when you mouse over the dosimeter badge that says "Radiated" in the top‑left corner of the screen. The sickness has twenty stages, as shown in the table to the left.
Radiation continues to build up until it reaches 111% but there are no additional effects associated with going past 100%.
Taking RadAway will reduce your current radiation level by 50%.
Radiation can be purged instantly by doctor NPCs who can be found in most major locations.
Note: Occasionally, you may encounter inventory descriptions with phrases such as "+200 Radiation." To convert these "radiation points" into irradiation percentages, divide by 18. For example, the Radiated Blood Pack's "-100 Radiation" is roughly equivalent to -5% displayed irradiation, and Radiated Ear's "+200 Radiation" is roughly equivalent to +11% displayed irradiation.
Slow
Slow is a non-stacking debuff that reduces the affected character's movement speed while increasing its attack delay.
The severity of a Slow is governed by two parameters: power, which determines the percentage by which the two stats are modified, and duration, which determines how long the Slow remains active.
When another Slow is applied to a character that already has an active Slow debuff, the duration is always updated to match that of the new Slow, but the power is only updated if the new value exceeds that of the already active Slow.
- Critical hits have a chance to apply a 20-second [20% x critical tier] Slow; see critical tables for details.
- Cyborg's critical hits have a chance to apply a 60-second [40% x critical tier] Slow instead.
- Defensive Belt (armor perk) applies a 40% Slow to attackers that lasts up to 11 seconds (or up to 17 seconds for Hubologists).
- Nightmare Defense (legendary armor perk, rank B) applies a 60% Slow to NPC attackers.
- 40mm Ice Edition (T4 ammo) applies a 5-second 100% Slow on hit.
- Eyebot (Robot's transformation) applies a 10-second 30% Slow on hit with Damage Knives.
- Frozen Queen (weapon perk) adds Slow to your attacks, with power of up to 70% and duration of up to 4 seconds (or up to 80% and 8 seconds for Hubologists).
- Rad Shot (Alien weapon perk) adds a 2-second 90% Slow to your attacks.
- Heavy Handed (trait) grants your melee attacks a chance to apply a 10-second 50% Slow on hit.
- Heretical Assault (PvE perk) applies a 5-second 80% Slow to the NPCs you hit.
- Random Boy (class perk)'s Strike has a chance to apply a 5-second 100% Slow on hit.
- Super Mutant applies a 10-second 30% Slow to attackers.
- Deathclaw (class perk), when equipped with a Punch Weapon, emits a persistent 15-hex PvP Slow aura that scales with the Heavy Handed malus.
- Antidote (drug) instantly removes Slow from the character that takes it.
- Med-Tec Antidote (drug) removes all negative status effects, including Slow.
- Coolheaded (level perk) reduces the duration of Slows applied to you by 30%.
- Hit and Run (level perk) reduces the duration of Slows applied to you by 50%.
- Adrenaline Rush (level perk) grants +8% chance to negate Slow (critical effect only) for each point of Charisma.
- Bonus Attack Speed (weapon perk) provides up to 60% reduction to the attack-delay penalty of Slows applied to you. Hubologists can get up to 100% reduction at rank S+.
- Speed Mechanism (armor perk) reduces the Slow power of incoming attacks by up to 22% (or up to 40% for Hubologists).
- Deathclaw (class perk) grants immunity to Slow.
- Leader (class perk)'s Mobility flag provides immunity to Slow.
- Radiated Eye (Cannibal drug) grants +5% Slow power.
- Soldier (class perk) gets +1 second to Slow duration and +1% to Slow power.
- Tier 2 Phoenix Module (combat implant) grants +10% Slow power and extends Slow duration by 5 seconds.
- Deathclaw (class perk) gets +1% damage protection per 1% of the power of the Slow debuff that applies to the attacker.
- Slow resistance reduces the Slow power of incoming Slow effects by a flat amount.
- Intelligence grants +2% Slow resistance per point.
- Mutie (drug) grants +10% Slow resistance and reduces the duration of Slows applied to you by 50%.
- Raider reputation of -901 or below reduces your Slow resistance by 10%.
- Spider Boss's blessing grants +10% Slow resistance, and adds a 4-second 20% Slow to your attacks.
Weakness
Weakness is a stacking debuff that subtracts 1% from one of the main six damage resistances in a fixed loop: normal → laser → fire → plasma → electrical → explosive.
| Weakness penalty breakdown | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
The table below is designed to help you quickly calculate your resistance penalties based on your Weakness stack count.
Here's a step-by-step explanation of how to use the table:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||
The following items interact with the Weakness mechanic:
- Med-Tec Antidote instantly removes all Weakness stacks.
- Perception grants +1% chance to resist Weakness per point.
- Electrical damage applies
20 - target's PerceptionWeakness stacks on the target. - Critical hits have a chance to apply Weakness to the target (ranged attacks aimed at arms only).
- More Critical Damage (weapon perk) allows your crits to apply additional Weakness stacks on your target.
- Heresy Shot (Alien-exclusive weapon perk) applies 3 Weakness stacks on hit.
- Leader (class perk) applies 2 Weakness stacks on NPCs with every hit.
- Random Boy (class perk) has a chance to apply 50 Weakness stacks on the target when attacking without a combat timer.
- Good Natured (trait) applies Weakness stacks to the character that has it when it kills an NPC.
Bleeding
Bleeding is a stacking damage-over-time debuff that deals at least 7 points of damage every 0.75 to 10.25 seconds and halves the target's healing received. The damage scales with the afflicted character's healing rate and the number of currently active Bleed stacks. A character can have a maximum of 5 active Bleed stacks at the same time; any additional incoming stacks are ignored. Each stack deals damage 5 times, then expires.
Bleeding damage per tick = target's healing rate / 4 * number of active Bleed stacks
Note that if you're a Priest, bleeding will completely disable your healing rate.
- Bloody (weapon perk) grants up to +35% Bleed damage (or up to +80% for Hubologists) and causes your critical hits to automatically apply Bleed stacks on hit.
- T5+ critical hits can cause bleeding even if you don't have the perk; see Critical hit#Critical tables for details.
- The Doctor skill removes 1 Bleed stack per use; this extends the skill's cooldown by 100 seconds unless you're a Paramedic.
- The First Aid skill removes 1 Bleed stack per use if you have the Healer level perk.
- Brotherhood Metal Armor grants immunity to bleeding.
- Cyborgs (class perk) are immune to bleeding.
- Leader (class perk)'s Vitality flag grants immunity to bleeding.
- Vitality (perk synergy) reduces bleeding's effect on healing received to -20%.
- Special Force Bonus (armor perk) grants up to +48% Bleed resistance (or up to +100% if you're a Hubologist).
- Atomic Savant (level perk) allows normal damage resistance to reduce bleeding damage.
- Eyebot's favorite weapon (Damage Knives) applies Bleed on hit.
- Nightmare Defense (legendary armor perk, rank S++, Hubologist-exclusive) inflicts Bleed stacks on NPCs whenever they attack you.
- Survivalist (armor perk) makes Hubologists immune to bleeding.
Burning
Burning is a stacking (up to 10 times) damage-over-time debuff applied in the form of Burn stacks by fire-based weapons, either directly or via "fire hexes," a fiery ground effect that inflicts both Burn damage and Burn stacks when stepped on.
Each time you take fire damage, you receive Burn stacks randomized between 1 and twice its source's weapon tier. Fire hexes apply one Burn stack at a time in addition to dealing one tick's worth of Burn damage immediately upon entry; remaining inside a fire hex will not apply further damage or Burn stacks.
Burn damage always deals 4-9 base damage per tick, regardless of the tier of the weapon that applied the Burn stacks. Each Burn stack corresponds to one tick of damage (see below for details).
Burn damage cannot be reduced; fire resistance does not interact with it, and Burn resistance only provides a chance to avoid it completely.
Burn damage from fire-based weapons cannot kill you, similarly to poison. Burn damage from fire hexes can kill you, similarly to bleeding.
Burn damage modifiers:
- Pyromaniac (level perk) grants +4 Burn damage.
- Tier 3 Dragon Module (combat implant, Cyborg-exclusive) grants +4 Burn damage.
- Burn damage from all sources is doubled against player characters below 50% of their maximum hit points.
- Burn damage from all sources is doubled again against player characters below 25% of their maximum hit points.
- Burn damage from all sources is doubled again against player characters below 10% of their maximum hit points.
- Leader (class perk)'s Unity flag grants Burn immunity.
- Inferno Armor grants Burn immunity.
- Your base Burn resistance depends on the type of your currently equipped body armor:
- Metal armor applies a -20% penalty to your Burn resistance.
- Combat robes grant +20% Burn resistance.
- Combat armor grants +50% Burn resistance.
- Leather armor grants +60% Burn resistance.
- Power armor grants +80% Burn resistance.
- Atomic Savant (level perk) causes your fire resistance to also provide an equal amount of Burn resistance.
- Survivalist (armor perk) grants up to +70% Burn resistance (or up to +100% if you're a Hubologist).
- Med-Tec Antidote (drug) removes all negative status effects, including Burn.
Burn ticks (advanced)
Each Burn stack deals exactly one tick of damage, then expires. Those applied directly by fire-damage attacks use a 5-second interval, whereas those applied by fire hexes use an 8-second interval as the base when calculating the timing of their next tick. Each type has its own stack counter and timer. The two timers run concurrently (each Burn stack type has its own separate queue).
The table below shows the tick schedule for Burn stacks applied at the same time; the initial damaging tick of such a package of stacks will occur after the full length of the longest tick interval associated with the package's number of stacks elapses, and the following ticks will happen at consecutively listed intervals. For example, if you have no Burn stacks, and a fire weapon applies 5 Burn stacks to you, you will receive Burn damage from those stacks 25, 45 (25+20), 60 (45+15), 70 (60+10) and 75 (70+5) seconds after their simultaneous application.
| Tick schedule for a single batch of Burn stacks | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
This is because whenever a Burn stack deals damage and expires, it triggers a scheduling update of its corresponding Burn stack type's timer that sets the timer to fire again after current_stack_count x base_interval. Any Burn stacks of the relevant type applied in-between scheduling updates have no effect on the one before they were added, and are only included in the current_stack_count of the next, i.e., when a new stack is applied while that type's timer is already running, the existing timer continues to its originally scheduled tick as if nothing happened. The new stack only increases the count used when that timer next recalculates.
Any Burn stacks you receive are added to your global Burn stack counter, which is displayed on your HUD. This counter is independent of the type-specific counters; once it reaches 10, any additional incoming Burn stacks will be ignored, regardless of their type; for example, if you are at 9 total stacks and receive a batch of 6, only 1 is accepted and the remaining 5 are discarded.
| Additional examples | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Example 1: Three direct and three fire-hex Burn stacks are applied simultaneously. The table below shows the application and Burn stack ticks as they happen in real time.
Example 2: Two direct Burn stacks and one fire-hex Burn stack are applied simultaneously; before any of them ticks, six additional direct Burn stacks are added by another attack. The table below shows the application and Burn stack ticks as they happen in real time.
Note that the direct tick at the 10-second mark was affected by neither the addition of six additional direct stacks (which only affected the following tick) nor the fire-hex tick (whose timer runs separately from the direct Burn stack timer). Example 3: Your character starts with no Burn stacks, then spends the next 6 seconds running back and forth through a field of fire hexes, acquiring 10 Burn stacks in the process. In this scenario, the first tick occurs 8 seconds after you acquire the first Burn stack, and the next 9 x 8 = 72 seconds afterwards. In addition, your character takes one tick's worth of Burn damage every time it moves onto a fire hex from any other hex, and while Burn stacks stop accumulating at 10 (due to the cap), the instant damage has no cap and, due to the doubling at 50/25/10% HP, can easily kill you if you're not careful. |
Addiction
Addicted characters suffer stat penalties when they're not under the effect of the drugs they're addicted to. Each drug has a unique addiction effect; see Drugs for details.
Characters with the Chem Reliant trait become addicted to the drugs they take automatically; everyone else is safe. To get rid of an addiction, you need to take a dose of Drug Antidote or reroll your character.
Poisoning
Poison stacks deal base damage equal to 2% of your max HP when they expire. If you reach 100 Poison stacks, they will expire all at once, dealing massive damage. Poison resistance allows you to negate a percentage of that damage. Radscorpions, Floaters, and Centaurs apply Poison stacks on hit. The Toxic Caves dungeon north of Klamath periodically applies Poison stacks to any player character inside. Taking poison damage immediately kills any character at or below 0 hit points.
The following items interact with the Poison mechanic:
- Endurance grants +5% poison resistance per point.
- Regulators (class perk) with Fast Metabolism (trait) receive only +2.5% poison resistance per point of Endurance.
- Luck grants +4% chance to avoid receiving poison stacks from NPC attacks per point.
- Snakeater (support perk) grants +30% poison resistance.
- Rad Resistance (support perk) grants +20% poison resistance.
- Antidote (drug) removes 25 Poison stacks from a character.
- Med-Tec Antidote (drug) removes all Poison stacks from a character.
- ULT (T1 WE stat) grants +25% poison resistance.
- S.ULT (T2 WE stat) grants +25% poison resistance.
- Poison reduces healing received by 50% (or by 20% if you have the Vitality perk synergy).
- Random Boy (class perk)'s Strike has a chance to apply 50 Poison stacks to the target.
- Random Boy has a chance to gain 50% poison resistance (lucky roll) or lose 25% poison resistance (unlucky roll).
- Eyebot (Robot transformation)'s favorite weapon type (Damage Knives) allows it to apply Poison stacks on hit.
- Atomic Savant (level perk) allows normal DR to reduce damage taken from poison.
- Survivalist (armor perk) increases your poison resistance cap by 10% and boosts your poison resistance by up to 60% (or 150% for Hubologist).
- Poisonous (weapon perk) applies up to 70 Poison stacks on the target (or up to 80 for Hubologist).
- Butcher (legendary weapon perk) allows lifesteal to work on poisoned NPCs.
- Rad Shot (Alien-exclusive weapon perk, rank A) applies Poison on hit.
Taunt
Taunt makes its targets unable to damage any characters other than the taunter. If the character that taunted you dies, the Taunt effect is immediately removed.
- Deathclaw (class perk)'s Rage taunts every hostile/neutral target on the map for 3 seconds.
- Soldier (class perk)'s Strike applies Taunt to the target for 8 seconds.
- Baiter (level perk) grants full immunity to taunts, and allows you to taunt all enemies within 30 hexes by using the Traps skill on yourself once every 2 minutes.
- Coolheaded (level perk) lets you recover from being taunted 30% faster than normal.
- Critical hits have a chance to apply Taunt to the target for 5 seconds.
Injury
Injured characters suffer significant stat penalties related to the affected body part(s); see the table below.
| Injury | Penalty |
|---|---|
 Crippled eyes |
|
 Crippled left/right arm |
|
 Crippled left/right leg |
|
- The Doctor skill allows you to heal crippled limbs.
- Leg injury is a common outcome of walking into a bear trap.
- Frag Mines set by characters with the Architect perk synergy always cripple their victims' legs.
- Explosive damage grants a chance to cripple limbs; the game rolls a random number between 75 and 250, and if it's lower than the damage dealt by the attack, a random injury is applied to the target.
- Critical hits have a chance to cripple the body part that the attack targeted.
- Iron Limbs (level perk) grants +8% resistance to crippled limbs (critical effect only).
- Deathclaw (class perk) receives a random injury when its Rage effect activates.
Fury and Rage
Fury stacks accumulate as a character gets hit and dissipate as it hits others. When the Fury cap is reached, the stacks are consumed to trigger the Rage effect.
The effects of Fury and Rage vary by class. Some classes, such as Combat Master, benefit greatly from both; others, such as Paramedic, are heavily penalized.
Many classes don't have any defined effects associated with the mechanic; those that do can be found in the table below:
| Class | Fury cap | Fury effect (per stack) | Rage effect (triggers when Fury cap is reached) |
|---|---|---|---|
| Alien | 25 | -1% damage protection | Gain 400% of the regular amount of weapon XP for 10 seconds |
| Chosen One | 25 | -1 Charisma | Set 2 random SPECIAL attributes to 1 for 20 seconds |
| Combat Master | 25 | +6% critical power | Ignore your targets' critical resistances for 10 seconds |
| Cyborg | 25 | +2% EMP damage resistance | Surround yourself with EMP explosions that deal 25% of your max HP for 10 seconds |
| Deathclaw | 25 | +5 melee damage | Receive a random injury and taunt everyone on the map except your faction for 3 seconds |
| Infantry | 25 |
|
Gain +40% DT and DR penetration protection for 10 seconds |
| Killer | 10 | -2% DR (PvP only) | Set attack delay to 700 ms for 10 seconds |
| Paramedic | 25 | -0.5% movement speed | Lose the ability to run for 10 seconds |
| Priest | 25 | -10% radiation resistance | Create a 20-hex healing aura that restores 10% of your teammates' max HP per second for 10 seconds |
| Raider | 25 | -3 action points | Gain 100% Lifesteal for 10 seconds |
| Random Boy | 25 | -1 to all damage thresholds | Lose your current random stat rolls and gain the ability to reroll immediately |
| Robot (Sentry) | 25 | +2 to all damage thresholds | Paralyze all enemies within 10 hexes |
| Soldier | 10 | +1% chance to suffer Paralysis every time you take action |
Lose the ability to use healing items or skills for 10 seconds |
| Super Mutant | 15 | +2% damage protection (PvP only) | Lose all damage protection and gain +500% damage for 10 seconds |
