Monday, May 21, 2018

The Mushroom Tower (part 2)

Okay, the party is in Highfield, the nearest village to the Mushroom Tower. They may have heard about more specific locations for the Tower, and can continue to seek out rumors if they need to.  There are some mushroom shaped rocks outside the village, and there are plenty of hills that could be fairy related (Is this one greener than the others?  Do the trees on this one grow taller?  Are the flowers here brighter?).  There is nothing resembling an enchanted lake anywhere near here (see below for details on the lake).

Everyone can see the comet in the sky, and the story of the Mushroom Tower is widespread, so there are a pile of adventurers in town.  The inn is full to overflowing, and every spare room and hayloft in the village is occupied.  Some more ambitious adventurers have set up camp in likely spots for the Tower to appear, and quite a few of them defend their turf against trespassers.  In general, higher level parties are more aggressive in their defense, while lower level parties are more willing to join forces to rout out whatever foul beasts happen to control the Tower.  If the PCs have had rivals or recurring enemies in past adventures, they are probably here now; if not, some of the groups here now will be jerks enough to become rivals soon enough.

General Layout:
The Tower rises from underground, telescoping into a sort of circular ziggurat shape.  It is piled high with earth accumulated over the centuries, shedding it from one level to the next slowly when it rains or quickly when a roof hatch levers open.  (When the Tower returns to its underground configuration, it will take time for this earth to refill the hole; in the mean time, it fills with stagnant rainwater.  There's your enchanted lake.)  The lubrication leaking from between the rings of the Tower's structure fertilizes some pretty strange mushrooms, forming concentric fairy rings; funny how none of the tales mention this.  Talking with some of the local oldsters might turn up this clue, or happening across the mushroom rings might be enough for a knowledgeable character.

Each ring of the Tower has a mission focus.  The outer ring (Ring V) contains mainly machine shops and bays for parking, maintaining and repairing ground vehicles (in re: the rumor table, tracked vehicles leave tracks that look like many small feet, hence the large roaring beasts with centipede legs; these robotic ground vehicles are used to gather raw materials from the surrounding area when the Tower is active).  The most likely entry for the PCs is one of these bays, either one that has opened to allow a ground vehicle to leave or a bay that has been damaged enough that characters can squeeze or force their way in through a fissure or warped bay door.  The next ring (Ring IV) has bays for ornithopter drones (resembling dragonflies, sadly none are operational).  The bays have hatches in the roof that open outward, causing any accumulated dirt to spill onto the Ring V.  Ring III contains missile silos (resembling arrows of fire when launched, most are empty now).  Every now and then during the early stages of the exploration of the Tower, a missile will launch skyward.  Ring II has barracks, mess halls, medical facilities, and cryosleep pods (if any of these are still operational, they wouldn't be good for PCs to experiment with).  Some of these are modified to support robots (servants of steel and bone).  The center circle (Ring I) is the command station, with rotating radar dish on top (remembered metaphorically as an all seeing eye).

Because all the rings form a disc when the Tower is contracted underground and a ziggurat when extended, every room that has a connection with an interior ring will have two doors, one at floor level and another about 30' higher.  At one point there was a stairway and/or catwalk that allowed access to the higher doors, but much of that has been salvaged and repurposed to keep the Tower running over the millenia.  The lower doors should be locked when the Tower is extended, but some have malfunctioned; if a PC opens an unlocked lower ring door or forces open a locked one, it opens into a black, yawning abyss (about 40' between Rings V and IV, adding 30 more feet for each ring inward).  Exploring down there will reveal the massive machinery used to raise and lower the Tower, as well as the reactor that powers the whole thing.  None of it will be of particular interest, but might prove dangerous for those who don't know what they're doing.

Wandering around the interior of the Mushroom Tower is not very safe.  At one point, it was a very well-equipped installation of a space-faring age, but it's been fighting a war for thousands of years without outside help.  To the characters, it is a place of wondrous magic/science, but to modern eyes, it would look like it's held together by spit and string; the chewing gum and duct tape have already been salvaged for more pressing needs.  Malfunctioning equipment lies around every corner, spitting sparks, leaking reagents, or teetering at the edge of collapse.  Even the working machinery has had much of the safety barriers removed to be used elsewhere.  "We need to repair this catwalk if we're going to access the coolant recycler, and no one's going to walk into this ventilation fan anyway, right?  Take the gridding down."

Some likely threats:
- Zombots: Originally the facility was supported by legions of technicians.  Cryosleep kept them alive far longer than their original culture and technological base, but eventually attrition forced them to build mechanical servitors.  Over time, the technicians all succumbed to the inevitable, and now even these servitors are a pale shadow of what they once were.  What were once constructed of plastic and metal are now cobbled together out of whatever materials are available: recovered plastics and metals, but also wood, leather, and bone are used structurally to shield and protect the vital and nearly irreplaceable circuitry and motors inside.  Zombots look horrifying, but are generally only concerned with maintaining the Tower and slowing the inevitable slide into oblivion.  They only attack characters if they are vandalizing the machinery or structure of the Tower.  Treat as zombies or skeletons, except they are unturnable (even the ones made mostly of bones).

- Vacuum tubes: They look like incandescent light bulbs.  They are very hot, and may shatter if touched.  1d4 burn damage/1d6 glass shrapnel damage.  A cascade of these exploding will ruin your day.

- Cables: These snake everywhere, along walls and across ceilings.  A loose one may emit showers of sparks at intervals, and will probably have a zombot on the way to repair it. They deal 1-6 d6 of shock if yanked loose or cut into.

- Massive gears: Used to open bay doors, raise or lower the Tower rings, or move heavy machinery inside the Tower.  If the gears start turning, characters touching them could be pulled in and crushed (save or die situation; a magnanimous DM could allow a character to get away with merely having a limb mangled beyond the abilities of medieval medicine to repair).

- Ventilation fans: Given the current state of the Tower, the ventilation ducts might be the best way into or out of a given area.  The fans might be spinning, or might be stopped, but activate at any time. Either way, coming into contact with them will do at least 3d6 damage.

- Leaky pipes: As ubiquitous as the cables, pipes run everywhere.  Many of them leak whatever they're carrying, whether that's superheated steam or caustic chemicals.  Give them 1-4 d6 of damage, or choose an appropriate spell effect to apply.

- Psychic radio:  An odd machine for communications.  Someone who knows how to use it may connect with another person's mind telepathically (this may allow a spying function similar to ESP if the DM permits).  Someone who doesn't know what they're doing (most PCs, at least at first) will likely suffer some kind of mental damage (loss of intelligence, amnesia, feebleminding, etc, DM's choice).  It is up to the DM how long it takes for a PC to work out the proper use of the machine.

The Final Boss:
Varrtir, the hero of old, is indeed the Master of the Mushroom Tower. He is found seated in the Command Center (Ring I), at this point not much more than a withered corpse trailing tubes and wires.  He speaks to the PCs through speakers in the walls, and displays information on a wall mounted screen.  If the party seems like they will attack, he will attempt to subdue them by flooding the room with a paralysis gas (Save vs Poison or Fortitude depending on system; treat as Hold Person spell).  If he can't parlay, he knows he will lose (he can't physically defend himself anymore...he's over 500 years old!) and will begin an automatic playback that will describe the true nature of the Tower and his plans to end the eternal war with the Celestial Sword.  The only way to end the playback at this point is to methodically destroy the screen and all the speakers in the room.  If the party is willing to speak with him, Varrtir will reveal the following information on his own, answering the characters' questions as he goes. 

The tales about him being compelled or forced to take the position after defeating the old Master are false.  He took the position on his own, after learning the true nature of the Tower; at that point, he had already slain the old Master.  The Tower was built in times long forgotten as a defense against the Celestial Sword, which is a ship of fiends from beyond the outer dark.  Or aliens, for a more modern audience.  Through the ages the Tower and the Sword have battered each other mercilessly, with neither being able to gain a decisive advantage as attrition has worn down the capabilities of both sides.  The Tower has had a particularly hard time of it, as adventurers have raided it time and again, thinking they were doing the will of the gods. 

Varrtir has a plan to send saboteurs to the Celestial Sword to wreak havoc there.  The same adventurers that have created such chaos in the Tower can surely help to finish off the Sword.  The previous missile launches have been other groups of adventurers.  He may or may not offer the PCs the chance to defend the world; at the DM's option, he may just gas them and send them without consent.

Because the characters are dealing with science beyond their previous experience, and because the players easily understand a lot of scientific ideas and terms, it is recommended that any questions Varrtir answers be couched in strange, unfamiliar terms.  Poul Anderson's Uncleftish Beholding is a pretty good example of real science with strange terms.  This Anglish dictionary should be helpful as well.  Confuse the players the same way their characters are confused.  They should in the end be pretty sure they're taking a rocket to attack a spaceship, but not 100% sure.

If the PCs decline to help, either another party of adventurers does the deed or the aliens win, and with the Mushroom Tower effectively done for, start sending landing parties to conquer the world.

If they decide to help, a zombot will help them to board a missile for launch.

Next time: Part 3 of the Mushroom Tower adventure, Attack on the Celestial Sword.

Friday, May 4, 2018

The Roe River

Probably not the most adventure inspiring river, but interesting nonetheless.

Then again, maybe it is kind of interesting.  For Giant Spring to gush forth enough water to make a river (as opposed to an intermittently wet ditch) there must be what amounts to an underground river there...

Wednesday, April 25, 2018

The Mushroom Tower (part 1)

I've been kicking around a few ideas for adventures, but I doubt I'll ever really put in the work to make them a real true "module" style adventure.  I have enough to kind of hang the whole adventure on, more than a seed, but not really enough to say it's a complete adventure. So I'm going to tag this as an "adventure skeleton" and go ahead and post something, rather than wait until I get it perfect (probably never).  Maybe I'll draw some maps, but probably not, because I see way better maps than I can draw out there every single day, and I kind of end up feeling like it's a straitjacket long before I actually get it done.  But I will do my damnedest to make it at least as playable as a one-page dungeon.


A golden comet has appeared in the sky.  At first there was just a little buzz among astrologers, sages, and the like, but at this point everyone is talking about it.  It is clearly visible with the naked eye as the sky grows dark, and everyone is certain, sovereigns to slaves, that it is the return of the Celestial Sword.

The Celestial Sword appears periodically -- the last time was about 500 years ago -- and signals a renewal of the war of the sky gods against against the wicked fae folk of the Mushroom Tower.  Stories vary from region to region, but everyone has heard some version of them growing up.

The characters roll d30 on the following table to determine what they remember hearing about the Mushroom Tower growing up.  At the Judge's option, characters with a lore-based background or class may get additional rolls.

Rumors and Tales
1 Huge creatures, fantastic's dragons that live in the Mushroom Tower.
2 Nothing alive could come back age after age. The Mushroom Tower is full of ghosts.
3 For their heresies, the inhabitants of the Mushroom Tower are cursed to disappear and reappear in time. This way, the gods can destroy them slowly and effortlessly, while giving the blasphemers no rest or recuperation.
4 No man knows what the things in the Mushroom Tower are. No man was meant to know.
5 What else would they be but giants? It's always giants defying the gods.
6-8 Don't know if it's Seelie or Unseelie, but it's definitely a fairie court in the Mushroom Tower.
9-10 The Mushroom Tower is topped by an all-seeing eye.
11-12 The Mushroom Tower is guarded by hordes of dead things armored in steel and bone.
13-14 They say the Mushroom Tower shoots giant arrows of fire at the gods. The gods must be winning; they say the Tower shoots fewer arrows each time it appears.
15-16 The Mushroom Tower spreads blights and fire on surrounding fields and forests whenever it appears.
17-18 Giant, roaring, smoke-belching beasts with many centipede legs emerge from the Mushroom Tower to denude forests and dig up rocks and dirt.
19-20 Huge dragonflies used to serve the fairies of the Mushroom Tower, but haven't been seen in ages.
21 The last time the Tower appeared, only Finngart, squire of Varrtir, returned, bringing with him a retinue of spirits of fire and smoke.
22-23 The Tower is itself alive. Not just like a mushroom is alive, but sentient and cunning.
24 There are some mushroom shaped rocks standing in the hills outside the village of Highfield. That's where the Tower appears, and that's why it's called the Mushroom Tower.
25 The Mushroom Tower is located under a fairy hill. It only looks like a tower from the inside.
26-27 When Finngart returned from the Tower, he brought enough riches to live like a king for the rest of his days. No one ever found so much as a penny of it after he died.
28 When Varrtir confronted and slew the master of the Tower, he was compelled to take his place. If the legends are true, Varrtir is the master now.
29 The Tower appears from an enchanted lake and disappears into it again when its time is up.
30 Roll twice and combine the two results imaginatively.

Travel to the vicinity of the Tower should take at least two weeks, and the old legends will be the main topic in every inn and tavern along the way.  Early on in the travel period, the party can roll 1d8 on the table to pick up more rumors.  At about a week and a half out, roll 1d8+8; at a week out, roll 1d8+15; and within three days' travel of the Tower's locale, roll 1d8+22.

The roads will be heavily traveled by other adventurers looking to loot the Tower, and by a few refugees looking to get away from the area before the wrath of the gods starts falling.  The prices of goods will shoot up due to the increased demand and decreased supply.  Parties who think to bring extra supplies to sell can rake in some money, perhaps double or triple list price.

Spoilers: More detail will be given in a future post, but the Judge should know now; the Mushroom Tower is a technological relic left over from an earlier age, a la Gus L's Fallen Empires and Land of 1000 Towers adventures.  (I guess that makes Patrick Wetmore's Anomalous Subsurface Environment the thematic grand-daddy here, but I still haven't picked that up.)  Most of the rumors on the table have a basis in truth, but have had 500 years to become entwined with fairy-tale standards to the point of being almost unrecognizable.   EDIT:  Looks like Gus has taken down his blog for some reason.  Luckily, someone saved his PDFs, or at least most of them.  Look here:

If you want to give some foreshadowing of the high-tech nature of the Tower, you can have the party find the remains of a smashed robot in some out-of-the-way niche on their journey there, or maybe there's a village with some piece of ancient technology that still works, like a spotlight or a motor they use to open and close the gate.

At any rate, I've let this blog sit too long without a post, so I'll end this now and get the next post up before two months passes by again.

Thursday, March 1, 2018

The Secret Strength of Chaos

Every human society is dedicated to Law.  Okay, maybe not a fantasy setting, some might actively dedicate themselves to Chaos, but even they don't go full Chaotic.  There's always some amount of Law in a mortal society.  In the real world, though, I stand by my original statement.

Now, it's not necessarily the same Law that they're dedicated to.  Those heathens to the east of our homeland worship the wrong gods, and hold the wrong colors holy.  (Meanwhile, in the east, they're complaining that the savages to the west don't even know how to propitiate the rain gods and that's why they live in a damn desert.  Also their numerology is heretical at best, if not outright blasphemous.)  But every real world society (and even over 90% of fantastic societies) have ideas about who the gods are, what makes them happy, who you can marry, what you can eat, how you should dress, how different segments of society should interact with each other, et cetera, ad infinitum, and most of them are not very chill about it when one of these rules/customs/laws is broken.

And when two different Laws collide, whether it's religious Law, political Law, economic Law, or sometimes even simple customary Law, you get strife.  Wars, border raids, clan feuds, gang violence, any kind of us-vs-them you can imagine.  And while a horde of poor Chaotic saps would get ground down pretty quickly and easily (without overwhelming numbers), these are powers of Law we're talking about here.  These guys are going to take their chains of command, and supply lines, and strategically placed fortifications, and they're going to enter into a long, bloody war of attrition, and fight until one side is unable to continue, unless both sides wear down at about the same rate and the whole thing just peters out.

Chaos can't exist where there is effective Law.  But in all those in-between areas where one Law ends and another begins, Chaos lurks.  It's just like magic that way...lurking in the in-between areas, like midnight (not one day nor the next), like Samhain (not one year, but not yet the next).  Chaos lurks in between Laws, and when those Laws go to war, Chaos thrives.

Thursday, February 15, 2018

Law is Discipline; Discipline is Strength

Some barely connected thoughts on alignment:

The most basic rule of the military is to know your place, both figuratively (within the chain of command) and literally.  If you're the squad leader, you know who your platoon leader (your immediate boss) is, and the company commander (his immediate boss) too.  You also know who your team leaders (your immediate subordinates) are, and all the soldiers they are in charge of.  If something happens to the platoon leader, one of the squad leaders will take charge of the platoon or the company commander will assign someone as the platoon leader.  If something happens to a team leader, one of the soldiers will take charge of the fire team or the squad leader will assign one of them as team leader.  A firm understanding of the chain of command allows the unit to keep fighting effectively even when suffering heavy casualties, because there is always someone in charge.

Looking at the literal side of things, soldiers knowing their place means there are no breaks in the camp perimeter for an infiltrator to sneak in through, and there are guards watching that perimeter to ensure that any attack is met with immediate resistance.  In battle, there are no breaks in the line, and shields form walls or fields of fire overlap into kill zones.  There are rules for who eats when, and how much, and there are rules for how to deal with equipment and how to deal with injuries and even, at times, when it is permissible to fight an enemy.  These rules have existed in some form or another since the dawn of civilization, and the closer an army (or any other branch of the military) adheres to them and to the discipline that such rules imply, the more powerful that army is.  The Roman army would march 20 miles in a day and build a fort at the end of the march, complete with walls and ditches, standardized streets and latrines.  They would fight in three established lines, using tactics designed to build on their strengths and cover their weaknesses.  Every soldier knew his place, and the Roman army regularly defeated armies of those who did not follow rules like these.

In fantasy RPGs, we often see a division of the game world into Law and Chaos. Those armies that most closely follow these types of disciplinary rules are by definition more Lawful.  And in our fantasy games as well as in literature and movies, we see a common trope of "small band of Lawful characters hold out against large horde of Chaotic monsters".  Sometimes, instead of a large horde of Chaos, there will be an equal or smaller number of Chaotic monsters, but each one is more powerful than a normal human.  Such battles usually end with Law victorious, and RPG campaigns usually progress with Law expanding into the wilderness, name-level PC stronghold by stronghold. 

Now, of course mere mortals rarely embody their own highest ideals, always falling short in some way.  A Lawful dwarf sentry might just fall asleep at his post, and Chaotic gnolls are rarely as free as they'd like unless they're the strongest in the pack or willing to strike out on their own.  But where mortal flesh is weak, the immortal spirits of the outer planes are mighty.

Everyone pretty much understands that the outer planes critters are more Good or more Evil than pretty much everyone on the material planes, but somehow this is often forgotten with regard to more Lawful or more Chaotic.  I mean, everyone agrees that the Seven Heavens and Twin Paradises are oh-so-good and no one there would ever be impolite in any way, and everyone knows that the Nine Hells and the Abyss are nasty places, and when they think about it the fact that modrons are very Lawful and slaadi are very Chaotic isn't a problem for anyone, but I've heard many people make the argument that the legions of the Abyss could roll right over all other planes combined.  To me this is completely forgetting the Law/Chaos aspect of alignment and the idea that denizens of the outer planes are exemplars of their alignment.

Sure, a horde of demons pouring from some vile portal would be devastating to the area they found themselves in, just from sheer numbers, but even at that, their Chaotic nature puts them at a disadvantage.  I don't doubt that the Dukes of Hell could call up every devil not immediately necessary for the regular day-to-day operations of Hell, get them organized into ranks and files, move them through a portal efficiently, and set about taking over strategic points in the invaded land.  If a powerful demon prince had a plan to open a portal capable of transporting a plane's worth of demons elsewhere, he almost certainly hasn't planned much past that.  It doesn't even matter how intelligent he is; he can see all sorts of nuances in a situation and come up with all sorts of stratagems to take advantage, and he will still be too impulsive to fully capitalize on his own plan, much less herd all those Chaotic cats it would take to make it happen. 

Oh yeah, big scary Demogorgon can whip them all into shape through fear...but Demogorgon can't be everywhere at all times, and when the cat's away the mice will play (to risk confusing cat metaphors).  Those lesser demons only fear Demogorgon when Demogorgon is in their face, and when he's off scaring the piss out of the last bunch of deserters, they'll end up slaughtering each other over a few baubles.  By the time he gets back to them, half will be dead and the other half will be scattered with their new-won treasures.  The best plan a demon prince can carry out is to herd a mess of demons through the portal, ignore the fact that a lot of them get left behind, and then let them do their thing once on the other side.  There will be no organized attack, just waves of disorganized yahoos going in all directions, not trying to take strategic positions, but trying to grab whatever catches their attention at any given time, and fighting among themselves as often as not.  Sheer numbers will sweep away resistance at first, but an organized defense will stop them cold at some point, and they will be powerless to overcome it.

And that's why the Bloodwar of 2nd Edition AD&D is not an entirely lop-sided cakewalk for the Abyss.  It was never a matter of nine planes versus 666, it was every bit of nine planes versus however many out of that 666 that happen to move in their direction at any given time, with the remainder working at cross purposes and in-fighting.

Wednesday, January 31, 2018

New River Spreadsheet and a Note on Meanders

Ok, I said I'd make a spreadsheet to figure out the velocity of floodwaters, so here it is:

It's just a quick and dirty calculation, assuming a triangular river cross-section, and absolutely not taking into account that the slope of the riverbed at its normal height and the slope of the adjacent area might not be the same, but it'll get you close enough for game purposes.

Note that if you already know the width, depth, and slope of a river, you can use the flood calculation pages to work out the velocity; just fill in the yellow areas and the green area will be your output.  It doesn't even have to be a flooded river, just any flowing water with known parameters.  The other cells in the spreadsheet are really just intermediate calculations that I didn't bother hiding.  It's just easier that way.  Besides, this calculation is a lot more straightforward than the first two pages, so a couple of unimportant but visible cells isn't going to busy up the spreadsheet too bad.

All that said, I was going to write a post working out all the details of meandering rivers.  Meanders follow certain mathematical rules, and knowing them can help you draw more realistic rivers.  But I'm not going to, because this guy has already done it.  Thanks, Dave Richeson.

Monday, January 29, 2018


Entrenchment is the last major characteristic in the Rosgen classification system. It is expressed as a ratio, giving the new width of the river if it were to be twice as deep as normal (as might happen in a 50-100 year flood).  This, not coincidentally, helps describe the immediate area surrounding the river.

The lower the entrenchment number, the deeper the river is cut into the landscape.  The higher the number, the more it lies along the general surface, spreading wider during a flood event. 

 For example, in our sample river map we've been following for the last several posts, the river in hex 0306 is ~90 feet deep, ~1950 feet across, and is type F, which is a deeply entrenched river type.  We find the entrenchment ratio is 1.2, so during a major flood event, the river in hex 0306 will be (90x2 = 180) 180 feet deep and (1950x1.2 = 2340) 2340 feet across.  The velocity should also be recalculated...I guess I should add a flood page to the spreadsheet.

Looking closer at this info we just found, you can see that if you move directly away from the river (perpendicularly), assuming that the river spreads equally to the left and right as the floodwaters rise, the land rises 90 feet (the added flood depth) in the course of 195 feet (half the added width of the floodwaters), giving the land there a slope of (90/195 = .46) .46, a very steep grade.  Tributaries flowing into the river here could easily be type Aa+ (remember that this river type isn't randomly generated in this system), although if they run in at an oblique enough angle the steep slope might be mitigated.  Also, characters will have an extra hard time crossing the river here.  As steep as the slope is, there probably isn't a road running down to the river, so no ferries or bridges either; if they have to get across the river right here, it'll mean a climb down to the river, a long swim, and then a climb back up on the other side.

Also worth mentioning, a 50 year flood, by definition, has a 2% chance of occurring in any given year, and a 100 year flood has a 1% chance.  Therefore, if you are using an annual events table to shape your campaign, there should be a 1-2% chance of needing to use the entrenchment ratio each game year...

This is the last addition to the river generation table, which is as follows:

Die Roll Slope DA C E F D B G A Aa+
1 0.0001 x x x x x

placed as needed
2 0.0003 x x x x x

3 0.0007 x x x x x

4 0.0015 x x x x x

5 0.002 x x x x x

6 0.004 x x x x x

7 0.006
x x x x

8 0.01
x x x x

9 0.02

x x x

10 0.03

x x x

11 0.04

12 0.05

13 0.08


Sinuosity 1 Min 1.4* Min 1.5* Min 1.4* 1 Min1.2* Min 1.2* 1.0 – 1.2 1.0 – 1.1

WDR 2d20 (d10x2)+12 d12 (d10x2)+12 (d10x4)+40 (d10x2)+12 d12 d12 d12

Entrench. >2.2** >2.2** >2.2** (d4/10)+1 1 (d8/10)+1.4 (d4/10)+1 (d4/10)+1 (d4/10)+1

* For these river types, roll 1-6 d6, divide by 10, and add 1, for a total of 1.1 to 4.6.  If this result falls under the minimum listed, use the minimum instead.
** These river types are associated with floodplains. If obvious floodplain boundaries (hills, mountains, etc) are apparent on the map, the river will fill that area during a 50-100 year flood. If boundaries are not apparent for whatever reason, the entrenchment ratio can be simulated by rolling an “exploding” d6 (ie, if a 6 is rolled on d6, keep it and add another d6, continuing to add d6s as long as 6s are rolled), dividing by 10, and adding to 2.2 (or (d6X/10)+2.2)