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Rust Monster

Medium · Monstrosity · CR 1/2 · Chaotic Evil

Source. Monstrous Menagerie

27 (5d8+5)

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)

Passive Perception 11

Traits

Metal Detection

The rust monster can smell metal within 30 feet.

Rust Metal

A nonmagical weapon made of metal that hits the rust monster corrodes after dealing damage, taking a permanent -1 penalty to damage rolls per hit. If this penalty reaches -5, the weapon is destroyed. Metal nonmagical ammunition is destroyed after dealing damage.

Actions

Antennae

The rust monster corrodes a nonmagic metal object within 5 feet. It can destroy up to a 1-foot-square portion of an unattended object. If the object is worn or carried the objects owner makes a DC 11 Dexterity saving throw avoiding the rust monsters antennae on a success.

Bite

+3 to hit, reach 5 ft (1.5 m). Hit: 1d8+1 piercing damage.

Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 5 (1d8 + 1) piercing damage.

Metal shields or armor the rust monster touches with its antennae corrode, taking a permanent -1 penalty to its AC protection per hit

If the penalty reduces the armors AC protection to 10 the armor is destroyed. If a metal weapon is touched it is subject to the Rust Metal trait.

Reactions

Defensive Bite

When the rust monster is hit by a melee attack made by a creature it can see within 5 feet, it bites the attacker.

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 15 and possesses 27 hit points (derived from 5d8+5).

GM Tips: Using Rust Monster

2 tips available

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

Minion Strategy: Use as scouts or minions for larger threats
Group Tactics: Group 3-4 together to pose a moderate threat

Player Guide: Facing Rust Monster

2 strategies available

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

Easy Target: This creature is weak - focus on other threats
Group Threat: Multiple can be dangerous - use area attacks

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.