Fallout Shelter Dweller Health Calculations

Fallout Shelter's dweller health system is complex, involving radiation exposure, stimpak usage, and natural health decay. This guide explains the calculations behind dweller health management and provides tools to optimize your shelter's health metrics.

Health Calculation Basics

Dweller health in Fallout Shelter is measured in health points (HP) ranging from 0 to 100. Several factors affect a dweller's health:

Radiation exposure from the wasteland
Stimpak usage to heal radiation damage
Natural health decay over time
Special abilities and traits

The base health calculation formula is:

Health = Base Health - Radiation Damage + Stimpak Healing - Health Decay

Each component affects the dweller's overall health status, which determines their ability to work and perform tasks.

Radiation Effects

Radiation exposure is the primary cause of dweller health decline. The amount of radiation damage depends on:

Time spent outside the vault
Radiation level of the wasteland location
Dweller's radiation resistance trait

The radiation damage formula is:

Radiation Damage = (Radiation Level × Time Outside) × (1 - Radiation Resistance)

Radiation levels range from 0 (safe) to 100 (extremely dangerous). The radiation resistance trait reduces damage by 10-30% depending on the trait level.

Stimpak Usage

Stimpaks are the primary way to heal radiation damage. Each stimpak provides a fixed amount of healing, but:

Stimpaks are limited resources
Overusing stimpaks can lead to addiction
Different stimpak types have different healing values

The stimpak healing formula is:

Stimpak Healing = Stimpak Type × Healing Multiplier × (1 + Addiction Penalty)

Common stimpak types include:

Stimpak: 25 HP
Super Stimpak: 50 HP
Jet: 75 HP

The addiction penalty reduces healing effectiveness by 10% per addiction level.

Health Decay

Even without radiation, dwellers experience natural health decay due to:

Aging
General wear and tear
Special abilities that consume health

The health decay formula is:

Health Decay = Base Decay Rate × Time × (1 + Aging Multiplier)

The base decay rate is 0.1 HP per hour, and the aging multiplier increases by 0.1 for each year of age.

Example Calculations

Let's look at a practical example to illustrate these calculations.

Example Scenario

Dweller: Sarah, 30 years old, Radiation Resistance trait (20% reduction)

Activity: 8 hours outside at a radiation level of 50

Stimpaks Used: 2 Super Stimpaks (50 HP each)

Time Inside Vault: 16 hours

Resulting Health: 85 HP

Calculation steps:

Radiation Damage: (50 × 8) × (1 - 0.2) = 320 × 0.8 = 256 HP damage
Stimpak Healing: (50 × 2) × 1.0 = 100 HP (no addiction)
Health Decay: 0.1 × 24 × (1 + 0.3) = 2.4 × 1.3 = 3.12 HP
Final Health: 100 - 256 + 100 - 3.12 = 85 HP

This example shows how radiation exposure and stimpak usage interact to determine a dweller's health status.

Frequently Asked Questions

How often should I check my dwellers' health?

Check health daily, especially after sending dwellers outside. Radiation damage accumulates quickly, and stimpak usage should be planned accordingly.

What's the best way to manage radiation damage?

Combine radiation resistance traits with strategic stimpak usage. Prioritize dwellers with high radiation resistance for outside work.

How does age affect health decay?

Each year of age increases the aging multiplier by 0.1, accelerating natural health decay. Younger dwellers maintain health longer.

Can I prevent health decay completely?

No, all dwellers experience some health decay. The goal is to minimize it through proper management and trait selection.