Table of Contents
The Unyielding Force of Tsunamis
Coastal areas may offer idyllic vacation spots, but they become ground zero when tsunamis—commonly but inaccurately referred to as tidal waves—unleash their fury. Tsunamis are born from violent geological events on the ocean floor, such as earthquakes or undersea volcanic eruptions. Unlike shock waves in solid matter, which dissipate quickly, the initial burst of energy from these cataclysmic events is absorbed and propagated by the surrounding ocean water with minimal loss of intensity.
Imagine the consequences: A tsunami can traverse thousands of miles across open water and still strike with formidable force upon reaching land. Think of dropping a pebble into a pond and watching the ripples spread, then scale that effect by millions in terms of both speed and water volume. That gives you a basic understanding of even a relatively ‘mild’ tsunami.
Warning Signs and Critical Timelines
For those standing near the shore and gazing at the ocean, the approaching wave becomes visible when it’s approximately half a mile away. At this point, you have an extremely limited window—less than 30 seconds—to react, given that the tsunami’s speed often exceeds 150 miles per hour. In the final moments before impact, expect the wave to tower at least 75 feet high and extend 500 feet in length, translating to nearly 30 million gallons of water for even the smallest of tsunamis.
The Aftermath: Inland Impact and Terrain Factors
Once the tsunami makes landfall, it may surge miles inland before exhausting its energy. Though the velocity drops significantly upon hitting land, the millions of gallons of water still flowing at around 20 mph can cause extensive destruction. How far the wave penetrates and how fast it loses energy depends on the specific coastal terrain. If you’re standing hundreds of yards from a 5,000-foot cliff facing the ocean, you may not even feel a splash. However, if you’re 20 miles inland in a low-lying area, you’re almost as vulnerable as those on the coast.
Survival Odds and DM’s Judgment
Let’s be clear: If you find yourself directly in a tsunami’s path, survival chances are bleak. The initial impact is likely to be fatal. Even if you survive the first hit, the chances are high that you’ll be knocked unconscious and subsequently drown. Proficiency in swimming might save you if the wave has lost some of its initial force, but if you can’t swim or maintain buoyancy, even the wave’s dying moments can be lethal. In role-playing scenarios like Dungeons & Dragons, the Dungeon Master’s judgment will ultimately dictate outcomes, so be prepared for any eventuality.
Tsunamis are monumental forces of nature that can transform serene coasts into scenes of unimaginable devastation. Their power, speed, and the narrow window for reaction make them awe-inspiring, terrifying phenomena that demand our utmost respect and understanding.
Tidal Waves/Tsunamis: Oceans Unleashed
Coastal areas may be ideal for relaxation, but they can quickly turn into danger zones when a tsunami strikes. These colossal waves are birthed by seismic activities like earthquakes or volcanic eruptions beneath the ocean floor. Unlike shockwaves traveling through solid matter, tsunamis retain their energy and can traverse thousands of miles with minimal loss in force. Upon sight from half a mile away, you have less than 30 seconds to react, given its speed of at least 150 mph. The incoming wave will be a minimum of 75 feet tall and 500 feet long, carrying nearly 30 million gallons of water with it. Depending on the geography, the wave can travel several miles inland, causing widespread destruction.
Tsunami Damage Chart for Gameplay
| Situation | Perception Check | Strength Check | Damage (Points) | Rounds Lasting | Other Effects |
|---|---|---|---|---|---|
| Tsunami Approaching | DC 15 to notice half a mile away | – | – | – | 30 seconds to react |
| Direct Hit from Wave | – | DC 25 to withstand | 4d10 | Instant | Knocked prone, carried by wave |
| Impact with Debris | – | DC 18 to avoid | 2d8 | Instant | Additional damage, potential for unconsciousness |
| Subsequent Inland Rush | – | DC 15 to hold ground | 2d6 | Varies | Reduced speed, potential to be swept away |
| Collateral Inundation | – | DC 12 to maintain footing | 1d4 | 3-5 rounds | Difficult terrain, reduced speed |
Notes:
- “Perception Check” indicates the difficulty class (DC) for characters to notice the incoming wave.
- “Strength Check” specifies the DC for a Strength Check to avoid or mitigate effects.
- “Damage (Points)” indicates the dice roll for calculating how much damage a character takes.
- “Rounds Lasting” shows the duration of the specific situation in-game rounds.
- “Other Effects” outlines any additional hazards or consequences.
Remember, these values and conditions are suggestions and should be adjusted according to the Dungeon Master’s discretion.
The Dynamics and Dangers of Floods and Flash Floods
Floods are a consequence of water’s fundamental properties: flowing from higher to lower elevations and filling available space. When a “container” like a river or lake can’t hold the excess water, it spills over, inundating adjacent areas. Floods often occur due to prolonged heavy rainfall in low-lying regions, or in climates where unusually high temperatures rapidly melt snow cover, especially when the ground is frozen and less absorbent.
Factors Influencing Floods
In most cases, flooding occurs next to rivers or lakes fed by rivers. As excess rain or melted snow travels downhill, it accumulates in these bodies of water. When the river or lake can’t contain the increased volume, it overflows its banks, leading to flooding. In winter and spring, the situation can be exacerbated when thawing temperatures transform months of accumulated snow into an overwhelming deluge, especially if the ground is frozen and unable to absorb water.
Flash Floods: Speed is of the Essence
While regular floods build gradually, flash floods are an entirely different beast. Typically short-lived but highly destructive, flash floods can inundate an area within minutes, compared to the slower pace of conventional floods that might take days to recede. Flash floods are most common in hilly or mountainous terrains, where heavy rainfall runs down slopes, collecting in low-lying areas before rushing further downhill. In its descent, the flood gains both volume and speed, transforming from a mere trickle to a raging torrent capable of moving 30 to 50 miles per hour within a matter of minutes.
Proactive Measures and Survival Strategies
To avoid a flood, one must simply distance themselves from the vulnerable area in advance. Regular floods usually offer some lead time for evacuation. However, flash floods can strike with little warning. Avoiding high-risk areas like mountain passes or gullies during or immediately after a rainstorm is critical.
If you’re caught in a flash flood, your swimming proficiency could be a lifesaver, although you may still sustain injuries from being hurled against rocks, trees, and other obstacles by the force of the water. If you’re not proficient in swimming, survival hinges on finding a secure spot quickly. You might be able to grab onto protruding objects like rocks or trees to wait out the flood, but holding on will be a test of your strength. A successful Strength Check will indicate you’ve secured your grip, but this check will need to be repeated to maintain your hold as the flood continues.
Duration and Aftermath
Flash floods are generally short-lived, lasting 10-15 rounds at any given point along their path. Even after the flood recedes, affected areas will remain submerged under slower-flowing water for several hours, presenting ongoing risks.
In summary, floods and flash floods are distinct but equally formidable natural events. Understanding their characteristics, causes, and how they interact with the environment is crucial for anticipating their dangers and taking appropriate safety measures.
Flood and Flash Flood Damage Chart
| Situation | Strength Check Required | Damage (Points) | Rounds Lasting | Other Effects |
|---|---|---|---|---|
| Standard Flood | – | – | Varies, usually prolonged | Difficult terrain, reduced speed |
| Caught in Overflow | No | 1d4 | 2-4 rounds | Potential to be knocked prone |
| Trapped in Rising Water | No | 1d6 | 5-10 rounds | Disadvantage on actions & attacks |
| Flash Flood | Strength Check Required | Damage (Points) | Rounds Lasting | Other Effects |
|---|---|---|---|---|
| Initial Hit | Yes | 2d6 | Instant | Knocked prone, carried by flood |
| Slamming Into Obstacle | Yes | 1d3 to 1d6 | Instant | Additional damage, possible unconsciousness |
| Struggling to Hold On | Every 2 rounds | 1d4 | 10-15 rounds | Failure means being carried further by flood |
| Post-Flood Terrain | – | – | 3d8 hours | Difficult terrain, potential minor injuries |
Notes:
- “Strength Check Required” indicates whether a character needs to make a successful Strength Check to avoid or mitigate damage or other negative effects.
- “Damage (Points)” outlines the dice roll needed to calculate how much damage a character receives.
- “Rounds Lasting” specifies how long the flood or flash flood situation lasts in-game rounds.
- “Other Effects” lists additional consequences or hazards characters might face.
Remember, these figures are subject to Dungeon Master discretion and can be adjusted to better fit the thematic or challenge level of the campaign.
Environmental Hazards: Avalanches, Rockfalls, and Mudslides
Avalanches
Introduction
Snow-packed mountains are idyllic to look at but carry with them the deadly force of avalanches—a turbulent storm of snow, ice, and rock that sweeps away everything in its path. When the tension between the layers of snow reaches a tipping point, the mountain unleashes its icy fury.
How it Happens
Avalanches require a unique set of conditions: a slope angled between 25 and 60 degrees, a snowpack of at least 12 inches, and temperature conditions that are prone to rapid fluctuation. The more these variables align, the greater the likelihood of an avalanche event.
Mechanics and Gameplay
Characters adventuring near avalanche-prone zones should be aware of the risks. The Dungeon Master will require a Dexterity saving throw for anyone caught in the path of an avalanche. Success allows the character to take appropriate evasive actions, possibly clinging to a rock or tree for dear life. Failure will result in the character being swallowed by the mass of sliding snow.
Potential for Damage
Characters trapped in the avalanche suffer significant HP damage ranging from 2d10 to 3d20, depending on the size and speed of the avalanche. It’s possible to halve this damage by curling into a protective ball, a technique that can be executed upon a failed saving throw. In addition, characters must make a Constitution saving throw to prevent falling unconscious if buried by the snow. Air is limited and can last between 5 to 10 rounds, depending on the Dungeon Master’s discretion (rolled as 1d6+4).
Rockfalls
Introduction
The rumble that precedes a rockfall is a harbinger of the avalanche of boulders and stones that will soon descend. Whether triggered by an earthquake or simply the erosion of time, rockfalls are quick, brutal, and indiscriminate in their destruction.
How it Happens
Rockfalls are most likely to occur on steep cliffs or mountainous terrains, especially after a seismic event or a substantial downpour. The conditions that set off a rockfall are often unpredictable, making them dangerous obstacles.
Mechanics and Gameplay
When a rockfall is triggered, characters within the affected area are obliged to make a Dexterity saving throw. A successful throw means they have dodged the worst of the falling debris, but a failed attempt leaves them battered by the rocks.
Potential for Damage
The impact damage can vary from 2d8 to 3d12 HP, depending on the size and speed of the falling rocks. In more severe cases, a Constitution saving throw is necessary to avoid being stunned for 1 to 2 rounds.
Mudslides
Introduction
When the earth itself turns against you, the result is a mudslide—a viscous river of soil, water, and debris that engulfs everything in its path. Particularly common in steep areas with loose soil, mudslides are often triggered by heavy rains.
How it Happens
Mudslides occur in places where the earth is poorly compacted and is mixed with an excess of water. Torrential rains saturate the soil, creating a slurry that can no longer hold its form.
Mechanics and Gameplay
In the event of a mudslide, characters in the danger zone must make a Strength saving throw. Success enables them to maintain their footing and avoid being carried away; failure leads to their being swept off their feet and carried by the mudslide.
Potential for Damage
The HP damage ranges from 1d8 to 2d10, based on the density and speed of the mudslide. A failed save might also require a Constitution saving throw to avoid being knocked prone.
Summary Chart(s)
| Hazard Type | Saving Throw Type | HP Damage Range | Additional Effects |
|---|---|---|---|
| Avalanche | Dexterity | 2d10 to 3d20 | May require Con save for unconsciousness, limited air supply |
| Rockfall | Dexterity | 2d8 to 3d12 | May require Con save for stun |
| Mudslide | Strength | 1d8 to 2d10 | May require Con save for prone |
Quicksand: The Treacherous Terrain of Swamps and Wetlands
Introduction
While it might be the stuff of classic adventure films and novels, stumbling upon a patch of quicksand in real life—or in a role-playing scenario—can be a hair-raising experience. Quicksand can appear in swamps, marshes, or other wet, low-lying areas, creating a unique obstacle for adventurers and explorers. Contrary to popular belief, quicksand doesn’t ‘suck’ you in, but that doesn’t make it any less dangerous. Here’s a comprehensive guide on understanding and navigating quicksand terrains.
What is Quicksand?
Quicksand is a geological phenomenon where water saturates the ground so thoroughly that it creates a mixture resembling a thick, viscous liquid. Contrary to its name, quicksand isn’t limited to sandy terrains; it can also consist of muddy earth. What distinguishes the ‘sandy’ from the ‘muddy’ quicksand is the level of viscosity and the rate at which a person might sink.
Sandy vs. Muddy Quicksand
Sandy Quicksand: More treacherous due to its thinner consistency, which allows a person to sink more quickly.
Muddy Quicksand: Thicker, thus providing more time to react, but no less dangerous in the long term.
Myths Debunked
- Suction: Contrary to folklore and cinema, quicksand doesn’t suck people under; rather, people sink due to the ground’s lack of solidity.
What To Do If You Fall In
- Keep Your Wits: Panic only exacerbates the situation.
- Tread Water: If you’re proficient in swimming, you can keep yourself above the surface by treading water.
- Move Horizontally: Try to make your way to a more solid area by moving along the surface.
Role of Companions
- Extend Help: A nearby companion can extend a branch or pole for the trapped individual to grab.
- Swimming Proficiency: Any rescuer venturing into the quicksand should ideally be proficient in swimming to avoid becoming another victim.
Conclusion
Understanding the nature of quicksand can be crucial for adventurers and explorers frequenting wet, low-lying areas. The key to survival isn’t just quick reactions but also knowing how to react. Maintaining composure, leveraging proficiency in swimming, and having aware companions can make all the difference.
Charts
| Type of Quicksand | Viscosity | Danger Level |
|---|---|---|
| Sandy Quicksand | Low | High |
| Muddy Quicksand | High | Moderate |
| Action | Effectiveness |
|---|---|
| Treading Water | High |
| Panicking | Low |
Viscosity is the measure of a fluid’s resistance to flow, essentially quantifying how “thick” or “thin” the fluid is. High-viscosity substances like honey flow slowly and resist deformation, while low-viscosity substances like water flow easily and quickly.
