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Rust Monster

Medium · Monstrosity · CR 1/2 · Chaotic Evil

Source. Black Flag SRD

14 (natural armor)

1/2

Ability Scores

Core attributes and their modifiers.

STR

DEX

CON

INT

-4

WIS

CHA

-2

Overview

Category Monsters

Size Medium

Type Monstrosity

Alignment Chaotic Evil

XP 100

Initiative Bonus +1

Movement

Walk 40 ft (12.2 m)

Swim 20 ft (6.1 m)

Climb 20 ft (6.1 m)

Crawl 20 ft (6.1 m)

Senses

Darkvision 60 ft (18.3 m)

Tremorsense 30 ft (9.1 m)

Passive Perception 11

Saving Throws

Strength +1 Dexterity +1 Constitution +1 Intelligence -4 Wisdom +1 Charisma -2

Resistances & Immunities

Damage Resistances

Monstrosity Resilience

Traits

Iron Scent

The rust monster can pinpoint, by scent, the location of ferrous metal within 30 feet of it.

Monstrosity Resilience

The rust monster is resistant to exhaustion and to the frightened condition.

Rust Metal

Any nonmagical weapon made of metal that hits the rust monster corrodes. After dealing damage, the weapon takes a permanent and cumulative -1 penalty to damage rolls. If its penalty drops to -5, the weapon is destroyed. Nonmagical ammunition made of metal that hits the rust monster is destroyed after dealing damage.

Spider Climb

The rust monster can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Actions

Antennae

The rust monster corrodes a nonmagical ferrous metal object it can see within 5 feet of it. If the object isn't being worn or carried, the touch destroys a 1-foot cube of it. If the object is being worn or carried by a creature, the creature can make a DC 11 DEX save to avoid the rust monster's touch.
If the object touched is either metal armor or a metal shield being worn or carried, it takes a permanent and cumulative -1 penalty to the AC it offers. Armor reduced to an AC of 10 or a shield that drops to a +0 bonus is destroyed. If the object touched is a held metal weapon, it rusts as described in the Rust Metal trait.

Bite

+3 to hit, reach 5 ft (1.5 m). Hit: 2d6+1 piercing damage.

Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 8 (2d6+1) piercing damage.

Bonus Actions

Iron Dash

The rust monster moves up to half its speed toward a source of ferrous metal it can sense.

About Rust Monster

Rust Monster is a medium monstrosity with a Challenge Rating of 1/2. It has a chaotic evil alignment.

In combat, this creature maintains an Armor Class of 14 and possesses 23 hit points (derived from None).

GM Tips: Using Rust Monster

1 tips available

When using Rust Monster in your D&D 5e campaign, consider these tactical approaches:

Climbing Advantage: This creature can climb at 20 ft. It can use walls and ceilings for tactical positioning. Consider using 'Spider Climb' negation or fighting in open areas without vertical surfaces.

Player Guide: Facing Rust Monster

1 strategies available

When your party encounters this creature, keep these strategies in mind:

Climbing Defense: This creature can climb at 20 ft! It can use walls and ceilings for surprise attacks. Fight in open areas without vertical surfaces. 'Spider Climb' negation spells can help.

Encounter Building Calculator

Standard Party Encounter (4-5 characters):

This creature is a medium encounter for a party of 4 characters of level 1.

Solo Encounter:

A single character of level 2 (up to level 20) can face this creature in a medium to hard encounter.

Experience Point Thresholds:

Medium: 75 XP
Hard: 112 XP
Deadly: 150 XP

Based on D&D 5e Dungeon Master's Guide encounter building guidelines. CR roughly equals party level for medium encounters.

Frequently Asked Questions

What is the challenge rating of Rust Monster?: Rust Monster has a Challenge Rating of 1/2, making it appropriate for parties of level 0.5.
What type of creature is Rust Monster?: Rust Monster is a Medium Monstrosity, which affects how certain spells and abilities interact with it.