Summary
Environmental hazards or effects can prove to be an excellent wrinkle to add to yourDungeons & Dragonscampaign. The 2024 Dungeon Master’s Guide offers a handful of examples of these types of effects, but there are also a decent number of modules and other sourcebooks that offer DMs even more options to use for their table, one of which is Tasha’s Cauldron of Everything.
In this sourcebook, environmental hazards can take the form of Supernatural Regions, Magical Phenomena, or even Natural Hazards. All of these can be great for your campaign, but we’ve compiled the list below of the best for your table.
10Haunted
Do You Believe In Ghosts?
The first of these environmental hazards is a Supernatural Region that assumes that an entire space is ‘haunted.’ This can include decrepit manors or haunted forests. For Supernatural Regions, once a player enters the space, you can set a handful of triggers (such as casting a spell) to then subsequently roll on a random effect table.
For the Haunted environment, Tasha’s suggests triggers such as gaining the frightened condition, darkness, or the chime of midnight. Effects can include violent thunderstorms, resurrectionof undead creatures, or strange wisps of vapor appearing in the air around the players.
9Mirror Zone
It’s Just Your Reflection
Don’t be afraid of a little vanity. In Tasha’s Cauldron of Everything, Mirror Zones occur when extraplanar magical entities converge with reflections. If players have entered a mirror zone, the trigger effects can include the shattering of a mirror or the use of teleportation and illusion magic.
From there, Mirror Zone effects can include things like the explosion of a Hallucinatory Terrain spell, a creature gaining the benefits of the Blink spell, or the appearance of enemy mirror shards that attack players. you’re able to always use the effects table found in Tasha’s, or you can make your own effects depending on the flavor of your campaign!
8Eldritch Storm
Not Like Eldritch Blast
Magical zones throughout the world of Dungeons & Dragons can make regular storms take on an Eldritch, arcane quality to them. There are a handful of different types of Eldritch storms, including Flaywinds (extra strong winds), a Flame Storm, or even a Necrotic Tempest.
Each of these storms has its own magical effects. These are all greatfor nautical campaignswhere players must brave stormy seas. The most interesting of these storms is known as Thrym’s Howl, which creates icy wind that imparts cold damage and reduces players' ability to heal.
7Unearthly Roads
Take Me Home
The magic of the weave is everywhere in the world, and sometimes, this effect even creates magical roads between realms. When these Unearthly Roads occur, they allow players and characters to travel great distances in a matter of minutes.
Whenever a player discovers an Unearthly Road between two planes of existence, or two spots on the same plane of existence, they can travel 21 miles in the time it would take them to travel one normally. Typically, these Uneartlhy Roads require a specific key or item to unlock, and can’t just be accessed by anyone.
6Avalanches
Watch Your Echoes
Avalanches are a great way to keep your party on their toes when traversing a snowy mountainside. Per the rules in Tasha’s, a normal avalanche is about 300 feet wide, 150 feet long, and 30 feet thick. This can prove devastating for low-level parties, so use this effect sparingly.
However, you can use an avalanchefor a high-level partyrelatively easily. You’ll have players roll initiative to avoid or defend themselves from the avalanche. Twice per round, on initiative count ten and zero, the avalanche moves 300 feet. Anyone caught up in the avalanche is blinded and restrained and gains a level of exhaustion for every five minutes buried.
5Infested
Not For The Faint Of Heart
Sometimes, if under the thumb of giant arachnids or insects, an entire metropolitan populace can suddenly become infested. This environmental hazard is great for long-term campaign arcs, in which players must free a large populace from the thumb of a horde of creatures.
This is a Supernatural Region, meaning when players enter the space, they can trigger various effects by either taking a short or long rest in the area, disturbing nests or webs, or anyone attacks a creature in the horde. Effects can include random encounters with the creatures, bioluminescence, or the appearance of additional webbing, forcing players to move as though they are in difficult terrain.
4Psychic Resonance
Did You Just…Speak?
Sometimes, in the world of Dungeons & Dragons, players can enter a space or realm in which strange psychic limerences occur. This can create forced telepathy, or allow certain creatures that know no languages to suddenly be able to speak. This means that even normal, non-magical beasts can potentially communicate with players in these zones.
Triggers for these realms can include creatures becoming charmed or frightened, or when a character encounters a powerful emotional experience. Other effects of Psychic Resonance zones can include increases to Intelligence checks or the inability to take a long rest.
3Unraveling Magic
Wild Magic, But Worse
You’ve heard of a Wild Magic sorcerer, but what about a Wild Magic zone? Unraveling Magic zones are areas in which the source of magic is corrupted or otherwise damaged. This can cause strange, unpredictable effects in spellcasting. Triggers for this supernatural zone can include charges spent on a magic item, any spell cast at first level or higher, or when a magical creature dies.
Effects that come after the trigger are vast and varied. You can either use the table presented in Tasha’s Cauldron of Everything to determine what happens in the zone, or you can even decide to use the Wild Magic Table from the 2024 Player’s Handbook instead.
2Mimic Colonies
Terrifying Treasure
Mimics are creatures that often take the form of treasure chests or other objects typically found in dungeons and other locales. However, a horde of mimics can even shapeshift to resemble an entire town, or all the furniture in a given room, taking a party by surprise!
This environmental hazard is a great way to surprise players. If players have a bastion, or keep of some kind, use a Mimic Colony to catch them by surprise in a place they think is safe. This will not only keep them on their toes going forward but will make for a highly memorable combat encounter. Tasha’s Cauldron of Everything has stat blocks and combat info for running a mob encounter with mimics.
1Flood
Hold Onto Your Hats
Lastly, Tasha’s Cauldron of Everything also has a ton of varying natural hazards you can use by mimicking the effects of certain spells. One such example is a flood, which can prove really fun for use in both natural settings and urban-sprawl campaigns.
When using a flood, you’re able to mimic the rules of a Control Water or Tsunami spell (Tsunami is more apt). Once you learn how to use spells in this way to run environmental hazards, you can use any number of spells to homebrew unique effects for yourself!
