Cloudkill

Level: 5
School: Conjuration
Class: Sorcerer, Wizard
Casting Time: Action
Range: 120 feet
Components: V, S
Duration: Concentration, up to 10 minutes

You create a 20-foot-radius sphere of yellow-green fog centered on a point within range. The fog lasts for the duration or until strong wind (such as the one created by Gust of Wind) disperses it, ending the spell. Its area is Heavily Obscured.

Each creature in the sphere makes a Constitution saving throw, taking 5d8 Poison damage on a failed save or half as much damage on a successful one. A creature must also make this save when the sphere moves into its space and when it enters the sphere or ends its turn there. A creature makes this save only once per turn.

The sphere moves 10 feet away from you at the start of each of your turns.

Using a Higher-Level Spell Slot. The damage increases by 1d8 for each spell slot level above 5.

Tactical Usage

Area Denial: Cloudkill creates a massive, moving zone of poison damage that forces enemy repositioning and controls battlefield movement. This 5th-level conjuration spell excels at disrupting enemy formations and denying strategic positions.

Optimal Timing: Most effective against clustered enemies or when you can force enemies into chokepoints. The moving sphere creates ongoing pressure throughout combat.

Resource Management: Uses a 5th-level spell slot - available from character level 9+. No material components make this resource-efficient for repeated use.

Target Selection: Position initial placement to maximize enemy exposure while allowing allies to avoid the expanding cloud.

Spell Combinations

Synergistic Spells:

Wall of Force/Wind Wall: Control cloud movement and direction
Entangle/Web: Hold enemies in the cloud's path for maximum damage
Misty Step/Dimension Door: Personal escape from your own cloud

Class Feature Interactions:

Sculpt Spells (Evocation Wizard): Cannot exclude allies from poison damage (conjuration spell)
Elemental Affinity (Draconic Sorcerer): No direct bonus (poison damage, not draconic type)
Wild Magic: May create unpredictable interactions with the conjured fog

Multi-Caster Coordination: Multiple cloudkill spells can create overlapping zones of denial, though they don't stack damage on the same target.

Material Component Details

Component Acquisition: No material components required - only verbal and somatic components needed.

Component Handling: Simple V, S casting allows for flexible deployment without resource management concerns.

Roleplay Opportunities: The lack of material components emphasizes the spell's connection to raw magical poison creation.

Economic Considerations: No ongoing costs make this an economical area denial option for frequent use.

Creator Notes

Encounter Balancing: Creates significant battlefield control that can turn encounters. Consider enemy mobility options and environmental factors.

NPC Usage: Powerful spellcasters can use this to force party movement or control access to key areas in dungeon environments.

Environmental Considerations: Strong winds disperse the cloud, ending the spell. Plan encounters with weather conditions in mind.

Campaign Integration: Excellent for siege scenarios, dungeon control points, or any situation requiring area denial capabilities.

Environmental Interactions

Terrain Effects: Indoor environments concentrate the cloud's effect. Outdoor areas provide more escape routes but also more wind exposure.

Weather Influence: Strong winds (including gust of wind) immediately disperse the cloud, ending the spell prematurely.

Structural Interactions: Walls and barriers can channel the cloud's movement, creating tactical opportunities for strategic placement.

Elemental Interactions: Fire or lightning might interact dramatically with the poisonous vapors, though no specific rules exist for such combinations.

Common Rulings & Clarifications

Timing Questions: Damage occurs when the sphere moves into a creature's space, when a creature enters, or when ending turn in the sphere.

Target Limitations: Affects all creatures in the area - cannot exclude allies from the poison damage and obscurement.

Duration Interactions: Concentration requirement means combat damage can end the effect. Plan protection for maintaining concentration.

Mechanical Interactions: Creatures only save once per turn regardless of multiple exposures. Heavy obscurement affects vision-based spells and attacks.

Alternative Applications

Non-Combat Uses: Area denial for controlling access to locations, forcing evacuations, or creating diversions during stealth operations.

Social Encounters: Threaten large groups without immediate violence, though this typically escalates rather than resolves social conflicts.

Exploration Applications: Clear dangerous areas of wildlife or monsters, create safe passage through contested territories.

Utility Functions: Pest control in large areas, though the lethality makes this extreme for most pest problems.

Same School: Other conjuration spells like web (2nd level battlefield control), wall of fire (4th level area damage), incendiary cloud (8th level fire version).

Similar Effects: Stinking cloud (3rd level non-damaging area denial), incendiary cloud (8th level fire-based upgrade).

Progression Options: Poison spray (cantrip single-target poison), stinking cloud (3rd level area control), incendiary cloud (8th level enhanced version).

Complementary Magic: Gust of wind (dispel enemy cloudkill), wind wall (redirect cloud movement), counterspell (prevent enemy casting).

Scaling Analysis

Level Progression: Excellent mid-level battlefield control that remains useful throughout campaigns for area denial and crowd control.

Upcast Benefits: Additional 1d8 damage per spell level makes higher-level casting significantly more lethal (6d8→7d8→8d8→9d8).

Campaign Phases: Peak effectiveness in mid-level play (9-15) where the damage and control remain threatening to most enemies.

Comparative Value: Solid damage-plus-control option that competes with other 5th-level spells for battlefield dominance.

Narrative Flavor

Casting Description: Noxious yellow-green vapors pour forth from your gesture, coalescing into a deadly sphere of roiling poisonous fog.

Effect Manifestation: The cloud moves with malevolent purpose, leaving trails of sickly vapor while maintaining its deadly concentration as it drifts across the battlefield.

Personal Style: Necromancers might create clouds with deathly imagery, while druids could manifest natural but toxic plant spores, and alchemist-wizards produce chemical reactions.

World Integration: Represents advanced poison magic that affects entire areas, often associated with toxic waste, alchemical warfare, or the corrupted magic of polluted environments.