The Legendary Lairs Core Collection combines the first two Legendary Lairs books with both Extreme Encounters: Weather and Terrain Omnibuses to create a complete modular encounter toolkit for Game Masters who want more cinematic boss fights, dangerous environments, evolving battlefields, and low-prep tactical encounters.

Together, these books transform ordinary encounters into memorable set pieces filled with adaptive enemy tactics, environmental hazards, magical terrain systems, weather effects, multi-stage boss fights, lair actions, recharge actions, traps, and battlefield complications.

Save $20 compared to buying separately.

Prefer print editions?

Legendary Lairs: Elemental Lairs

• Paperback available on Amazon US
• Hardcover available on Amazon US

Legendary Lairs: Unearthly Lairs

• Paperback available on Amazon US
• Hardcover available on Amazon US

Extreme Encounters: Weather and Terrain Elemental Omnibus

• Paperback available on Amazon US
• Hardcover available on Amazon US

Extreme Encounters: Weather and Terrain Unearthly Omnibus

• Paperback available on Amazon US
• Hardcover available on Amazon US

Designed for fast integration into existing campaigns, these plug-and-play systems work equally well for dungeon crawls, wilderness adventures, elemental campaigns, dark fantasy settings, planar expeditions, and high-stakes boss encounters.

Compatible with both the 2014 (5e) and 2024 (5.5e) rules.

What You’ll Get

• Legendary Lairs: Elemental Lairs (5e)

Plug-and-play elemental boss encounters featuring adaptive tactics, evolving battlefields, lair actions, recharge actions, traps, magical terrain, and multi-stage boss fights.

• Legendary Lairs: Unearthly Lairs (5e)

Dark fantasy lairs filled with cursed terrain, psychic horrors, plague-ridden battlefields, necrotic wastelands, shadow magic, and deadly supernatural encounters.

• Extreme Encounters: Weather and Terrain Elemental Omnibus (5e)

Dozens of weather effects, environmental hazards, magical terrain systems, monsters, and encounter complications for elemental or adverse weather adventures.

• Air – Magical cloud castle terrain, high elevation areas (including altitude sickness rules), lightning storms, thunderstorms, tornados, windstorms
• Cold – Magical cold terrain, blizzards, frozen lakes/rivers, hailstorms, snowstorms, thundersnow/sleet, winter storms, plus how winter weather impacts travel times
• Earth – Magical Elemental/Fey chaos, caves, chasm/cliffs, earthquakes, forests, hills/mountains, mines (with elevator and deadly gas rules), mud/clay, and quarries
• Fire – Magical fire terrain, burning buildings, fire devils (fire tornados), firestorms, lava flow, lava tubes, volcanic eruptions, and wildfires
• Water – Magical Fog Banks, beaches (rocks or sand), coastal sand dunes/sinkholes, floods (with waterborne disease rules), rain (light or heavy), rapids, river crossings (with or without a ferry), rough sea voyages (ship in storm rules), and waterfalls

The Elemental Omnibus collects these five Extreme Encounters: Weather and Terrain titles:

• Extreme Encounters: Weather and Terrain Unearthly Omnibus (5e)

Dozens more weather effects, environmental hazards, magical terrain systems, monsters, and encounter complications for supernatural or adverse weather adventures.

• Acid – Acidic vapors, acid rain, corrosive and slippery slime for Aberrations and Oozes
• Necrotic – Blighted wilderness, cursed ground, unholy ground, necrotic curses and diseases (including a flesh-eating zombie virus)
• Poison – Mutant vermin infestation, poison rain, poison vapors, sewers, swamps, and even fighting in or around a rotting a Huge or Gargantuan monster carcass
• Radiant – Holy ground, solar ground, lunar ground, badlands, deserts, heat waves, sand dunes, and sandstorms (dust storms)
• Spirit – Astral and Ethereal crossroads, ghostly wailing (haunted areas), psychic dreamscape, and soul storm (magical extraplanar weather)

The Unearthly Omnibus collects these five Extreme Encounters: Weather and Terrain titles:

Between all four books, you get:

• Hundreds of modular encounter combinations for dungeon crawls, wilderness adventures, boss fights, and campaign-scale encounter design.

• Systems designed for low-prep Game Masters who want faster setup and more memorable encounters.

Awards for Extreme Encounters Omnibuses

SILVER BESTSELLERS

— Awarded by DriveThru RPG (DTRPG)

Average Customer Rating

⭐⭐⭐⭐⭐

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Top Reviews

"The art for Elemental Lairs is incredible. I also like the layout. The pdf in particular has lots of links that can be used to jump to information easily. [It has] excellent suggestions for adjustments that can be made to games to make lairs and boss fights interesting, epic, and unexpected. Even outside of boss fights, much of it can be used to make more dynamic terrain encounters. Legendary Lairs: Elemental Lairs would be an excellent addition to any Game Master's collection."

— Marina, DTRPG customer, review for Legendary Lairs: Elemental Lairs

"MageGate has useful, usable, thematic lairs. The legendary and lair actions help flesh out how and why to use them, adding flavor to whatever level your encounters are set for."

— Robert, DTRPG customer, review for Legendary Lairs: Elemental Lairs

"...An absolute masterclass in mechanical depth for 5e boss encounters. The "crunch" is exactly what I look for—each lair provides a wealth of modular tools, from dynamic terrain and hazardous environmental effects to perfectly tuned Lair and Recharge Actions that make every encounter feel like a tactical puzzle rather than just a bag of hit points. What really sets this apart for my style is that these aren't just generic combat arenas; the book actively encourages GMs to weave the boss’s history and motivations directly into the environment, allowing for the kind of narrative cohesion that keeps players fully invested. If you want to elevate your climactic boss fights from simple skirmishes to epic, memorable showdowns, this is an essential addition to your DM toolkit."

— Neill W., Amazon UK customer, review for Legendary Lairs: Elemental Lairs

"If you’re looking for inspiration for your boss or their lair, this is, without a doubt, the best work out there."

— Amazon customer, review for Legendary Lairs: Elemental Lairs

"As good as Legendary Lairs: Elemental Lairs, the first volume? I’m even more inspired. Spooky and spectacular! So many creepy evocative names, effects, and creature ideas for a whole host of lair types. There’s so much flavor and crunch you won’t be able to resist adding new story wrinkles to your campaign."

— MageGate customer, review for Legendary Lairs: Unearthly Lairs

"Too often weather is neglected as an element of TTRPGs, perhaps because it’s too daunting to come up with all the mechanics, but here MageGate has done it for you. Super charge your games with this omnibus, loaded with conditions, effects, and everything else you’ll need to imperil your players in new and exciting ways."

— Amazon customer, review for Extreme Encounters: Weather and Terrain Elemental Omnibus

"Don’t just say ‘You’re walking through the forest.’ There can be so many other ways to bring the space to life! And once you do that [with this Elemental Omnibus] that could lead to some really cool storytelling. I really like this book for the flexibility of the options… really, really fun!"

— Splinterverse (YouTube Channel), review for Extreme Encounters: Weather and Terrain Elemental Omnibus



"This book has a lot of great information for any DM who's running an elemental campaign."

— Amazon customer, review for Extreme Encounters: Weather and Terrain Elemental Omnibus

"In a good D&D campaign, the scenery isn't just to look at. It's to navigate, do battle with, and use to your advantage. Extreme Encounters gives you a huge number of tools to develop fun landscapes."

— Amazon customer, review for Extreme Encounters: Weather and Terrain Elemental Omnibus

"Once again, MageGate has produced an invaluable resource for DMs. As well as rules for inserting magical or extreme terrain into your adventures, they also suggest magical items which might go with the area."

— DTRPG customer, review for Extreme Encounters: Weather and Terrain Elemental Omnibus

"Extreme Encounters: Weather & Terrain Elemental Omnibus: This book has a lot of great information for any DM who's running an elemental campaign."

— Amazon customer, review for Extreme Encounters: Weather and Terrain Elemental Omnibus

"This is a great resource for any GM running a campaign and wants to add unique terrain features for the party to deal with. I own the entire MageGate collection and highly recommend them."

— Pat, DTRPG customer, review for Extreme Encounters: Weather and Terrain Unearthly Omnibus

"Another stellar text from the Mage Gate team. A worthy addition to any DM's collection."

— Andrew, DTRPG customer, review for Extreme Encounters: Weather and Terrain Unearthly Omnibus

"This book (and the rest of the Extreme Encounters series) gives a whole slew of great options for making combat more interesting. Plus, it's got fun bonuses like a new exhaustion system and explanations of how character abilities interact with the environments."

— Amazon review of Extreme Encounters: Weather and Terrain: Acid (included in the Unearthly Omnibus)

"The new exhaustion rules seem balanced [and the book has] good ideas on magical terrain."

— Amazon review of Extreme Encounters: Weather and Terrain: Acid (included in the Unearthly Omnibus)

"Acid is a very challenging terrain for players. I like the rules for constant damage [in this book] that can be increased or decreased as desired by the GM."

— DTRPG customer review of Extreme Encounters: Weather and Terrain: Acid (included in the Unearthly Omnibus)

"As a DM who seems to attract very chaotic players, I'm always on the hunt for new and exciting ways to surprise them. This book offers a number of interesting (and, naturally, acidic) ways to do just that!"

— DTRPG customer review of Extreme Encounters: Weather and Terrain: Acid (included in the Unearthly Omnibus)

"It's full of tasty bits to fill in around the edges of your game."

— DM's Guild customer review of Extreme Encounters: Weather and Terrain: Acid (included in the Unearthly Omnibus)

"Good information on weather events including tornados. I recommend this book for anyone planning on a sky-based campaign."

— Amazon customer review for Extreme Encounters: Weather and Terrain: Air, included in the Elemental Omnibus)

"I was looking for some inspiration for encounters when [players are] flying around, and this provided a variety of different ideas and weather conditions. There were also a number of new and interesting [air and storm-related] magical items, which was very nice. Highly recommended!"

— Amazon Japan customer review for Extreme Encounters: Weather and Terrain: Air, included in the Elemental Omnibus)

"Good information. Finally some rules for Cloud Castles!"

— DTRPG customer review for Extreme Encounters: Weather and Terrain: Air included in the Elemental Omnibus)

"I am currently writing a winter-themed campaign for my DND 5e group [and] this book is going to help me a lot in my upcoming campaign. Definitely recommend."

— Amazon customer review for Extreme Encounters: Weather and Terrain: Cold, included in the Elemental Omnibus)

"Cold weather campaign? This book has you covered. I do recommend this book for any GM running an Arctic Adventure."

— DTRPG customer review for Extreme Encounters: Weather and Terrain: Cold, included in the Elemental Omnibus)

"Good rules for burning buildings and handling lava flows."

— DTRPG customer review for Extreme Encounters: Weather and Terrain: Fire, included in the Elemental Omnibus)

"Good book with some uncommon rules... fighting in narrow passages and on slopes are a must when actually running a group through a cave crawl."

— DTRPG customer review for Extreme Encounters: Weather and Terrain: Earth, included in the Elemental Omnibus)

"I got a lot of cool adventure ideas from this book! It has great, easy rules for running adventures in caves, hills, mountains, forests and mines. This book as well as the others will always find use at my table!!!"

— Amazon customer review for Extreme Encounters: Weather and Terrain: Earth, included in the Elemental Omnibus)

"Interesting rules including unholy ground."

— DTRPG customer review of Extreme Encounters: Weather and Terrain: Necrotic (included in the Unearthly Omnibus)

"The Necrotic book has some great terrains, creatures and magic items. It's a quick read. And these can be easily slid into any campaign. Great ideas and gets you thinking on how you can incorporate them in your game."

— Amazon customer review of Extreme Encounters: Weather and Terrain: Necrotic (included in the Unearthly Omnibus)

"Interesting rules, including cramped sewer fighting."

— DTRPG customer review of Extreme Encounters: Weather and Terrain: Poison (included in the Unearthly Omnibus)

"I like the balanced rules for heat waves. There are rules for Moonlit Ground [for celestials, fey, lycanthropes, etc.] which is something I have never thought of before when running a campaign."

— Amazon customer review of Extreme Encounters: Weather and Terrain: Radiant (included in the Unearthly Omnibus)

"Interesting book with unusual [Astral and Ethereal] rules. I especially liked the Soulstorm rules."

— DTRPG customer review of Extreme Encounters: Weather and Terrain: Spirit (included in the Unearthly Omnibus)

"It's good to see common sense rules for flooding, including waterborne disease."

— DTRPG customer review for Extreme Encounters: Weather and Terrain: Water, included in the Elemental Omnibus)

Preview of interior pages below.