Dungeon Grappling – Part 2, the Monster of Gravity

Thursday , 9, February 2017 12 Comments

Howard Pyle, Oil on canvas,
Size|in|27.5|17.875, 1909

In my previous column, I gave an example of how Douglas Cole’s Dungeon Grappling, could be used to add tension to a combat using the classic fight scene by Robert E. Howard. In this one, I discuss an adaption of the Dungeon Grappling rules of my own devising. Disclaimer: I did back the Kickstarter for this product, and I have had Mr. Cole’s input in the review of the example below in order to ensure I represented his approach fairly. I have received no money to endorse the product, nor do I receive any payment for these columns in general. I write these in the hope that some people might find them interesting or useful. Any mistakes or misrepresentations are my own. The approach I give below is not endorsed by Douglas Cole. It’s my own thought experiment riffing on his technique. 

It is quite common in fiction and film to jack up the stakes in a scene by having someone fall off of something and be hanging on for dear life. In role playing games this situation rarely comes up and is often resolved through all or nothing skill/attribute checks or saving throws. This approach is fine as far as it goes but, the extended will he/won’t he fall trepidation is missing and the high stakes get resolved too quickly. My idea for using the Dungeon Grappling rules for this is to model gravity as a monster and feats regarding gravity as the effects of being grappled by it. In which case gravity will have the following statistics:

Table 1 — The Monster of Gravity

Grapple DC: 10
Attacks: 1
Grappling Damage: See table 2
Grapple Attack Roll: Automatic
Control Maximum: NA
Condition Thresholds: NA but, always wins initiative.



Table 2 — The Monster of Gravity

 Size  Space Land Base Grappling Damage In water Base Grappling Damage
Fine ½ by ½ ft. × ¼ 1 0
Diminutive 1 by 1 ft. × 1/3 1d2 1
Tiny 2 ½ by 2 ½ ft. × ½ 1d4 1d2
Small  5 by 5 ft. × ¾ 1d6+1 1d3+1
Medium 5 by 5 ft. × 1 1d8+2 1d4+1
Large 10 by 10 ft. × 1.5 2d6+4 1d6+2
Huge  15 by 15 ft. × 2 2d8+8 1d8+4
Gargantuan 20 by 20 ft. × 3 3d8+12 3d4+4
Colossal 30 by 30 ft. or larger × 4 4d8+16 2d8

This “Monster” is used when gravity is attempting to drag a character down. I’ve come up with three situations to use this monster: climbing, swimming and tightrope walking.  You might be able to come up with others, if so please comment, I’m interested in extending this idea into other areas. At the end of this write-up are various situational modifiers for these activities as well as some specific rule variants for these activities. They are really in draft form so comments there are welcome as well. Note in Table 2 unlike in Dungeon Grappling, the size here is the size of the entity being grappled by gravity rather than the size of the person grappling. And, yes, I know gravity is constant but, the variable is there to represent a character who is moving, swinging, or otherwise oriented in unusual ways.

Like my previous example, I will demonstrate this through the example of a painting and a work of fiction. In this case, Morgan Robertson’s story “The Grain Ship” which was apparently inspired by the Mary Celeste incident. In the story a grain ship sailing from the US to Europe gets infested with rabies-infected rats.  The rats, one by one, bite the crew until all go mad and die. Eventually only the 2nd mate, Draper, is left alone with the 1st mate, Barnes, who also gets bit and goes rabid. Barnes chases Draper out onto the ship’s bowsprit trying to attack him. Howard Pyle, masterfully illustrated the scene. Draper and Barnes are both hearty sailors so, I gave them +1 for strength and a climb skill as 1st level thieves  of 87% for sailor related climbing tasks (rigging don’t you know) but, are otherwise normal low level men. In this example, which isn’t system specific I will also use the climb skill for tightrope walking – otherwise use whatever appropriate skill your preferred system might use.

Table 3 – Draper and Barnes

  Draper Barnes
Grapple DC: 12 12
Attacks: 1 1
Damage: unarmed Unarmed (special bite, rabid)
Grapple Attack Roll: 1d20+1 to Grapple 1d20+1 to Grapple
Grappling Damage: 1d8+1 1d8+1
Control Maximum: 10 10
Condition Thresholds: Grabbed (1-3); Grappled (4-5); Restrained (6-10); Incapacitated (11+) Grabbed (1-3); Grappled (4-5); Restrained (6-10); Incapacitated (11+)
HP: 6 6
AC: 9 9
HD: 1 1


The pivotal scene is here in red.

“He caught me on the forecastle deck and made for me, half mad from the disease, but wholly mad from his mental state. There was no escape except out the head-gear, and I went that way, with him after me. Out the bowsprit, on to the jib foot-ropes, and out toward the end I went, hoping to reach the martingale-stay and slip down it to the back-ropes. I did so, but he scrambled down, tumbling and clutching, and gripped me just abaft the dolphin-striker. His face was twisted in frenzy, and he growled and barked like a dog, occasionally breaking into a horrible, rat-like squeal. But he didn’t bite me; he simply squeezed me in both arms, and in that effort lost his hold on the back-rope and fell, taking me with him. We struck the water together, and his grip loosened, for he was now up against something too strong for him—the sound and sight and feeling of cold water.”

Schematic view of the bow of a ship, showing: A the martingale stayB the dolphin striker and C the bobstay. From WikipediaThe path Draper and Barnes follow is out onto the bowsprit then down A, past B, and onto C.

Round 1: Draper starts at the end of the bowsprit. Barnes is on the bow and walking along the bowsprit to attack Draper. Both Draper and Barnes are in a situation where gravity is in play. As gravity wins initiative and automatically hits, the DM rolls grapple damage for both. As they are both medium sized gravity get d8+2. Draper gets 7+2=9 CP (restrained, -5 attack and defense penalty). Barnes gets 2+2=4 CP (grappled, -2 attack and defense penalty).

Barnes wins initiative versus Draper and moves along the bowsprit. The DM makes the call that this is the equivalent of tightrope walking and treats it as such. He rolls his climb and barely succeeds with an 85 but, still earns him a -3 to grapple DC (making it seven). He rolls a d20 and adds one for his dexterity (note tightrope using dexterity as the ability modifier rather than strength) and subtracts two for being grappled and gets an 18+1-2=17 and hits. He rolls a d8+1 and get 6+1=7 CP which he uses to reduce the grapple CP on himself to zero. Barnes runs along the bowsprit and approaches Draper.

Now draper using his sailor skills Draper is retreating under the bowsprit. He attempts to slide down the martingale stay. He rolls a climb skill and gets a 54, a success which subtracts three from the Grapple DC making it 7. He rolls a d20 and adds one for strength against gravity’s Grappling DC of 7 and subtracts five for being restrained, and gets and 12+1-5= 8 and hits. He rolls a d8 for 5+3 = 8 control points. Draper uses all 8 to reduce gravity’s grapple to leave himself at 1 CP. Gravity has grabbed him but, he can still move and he slides down to the dolphin striker.

Round 2: Gravity always wins initiative and Draper ends us with 4 CP for a total of 5 CP due to his remaining 1 CP (grappled, -2 as before) and Barnes gets 9 CP (restrained, -5 as before).

Barnes wins initiative and follows Draper down the martingale stay. He rolls a climb skill and gets a 91 which means he does not subtracts three from the Grapple DC. Grapple DC stays a 10. He rolls a d20 and adds one for strength against gravity’s Grappling DC of 10 and subtracts five for being restrained, and gets and 16+1-5=12 and hits. He rolls a d8 for 3+1 = 4 control points. Barnes uses all 4 to reduce gravity’s grapple to leave himself at 5 CP. He’s reduced gravity’s hold to grappled (-2) and his move is reduced to half. But, it’s a short distance and he slides down to the dolphin striker to join Draper.

Draper wants to move away from Barnes and past the dolphin striker. He rolls his climb and gets 35 a success (-3 three the Grapple DC). He rolls a 12+1-2 =10 and hits. His d8+1 damage CP roll comes out 7+1=8 CP which he uses to reduce gravity’s hold on him to 0. Draper handily moves past the dolphin striker and onto the bobstays (the back-ropes in the text).

Round 3: Gravity always wins initiative and Draper ends us with 6 CP (restrained, -5 as before) and Barnes gets five for a total 10 CP (restrained, -5 as before).

Barnes wins initiative again and follows Draper past the dolphin striker. He rolls a climb and gets a 23 which passes, leaving his Grapple DC at 7. He them rolls d20 plus one for strength, minus five for restrained and gets 14+1-5-10 which passes. He rolls a 4+1=5 to reduce gravity CP on him to 5 (grappled, -2). Barnes can make a half move and makes it past the dolphin striker.

Draper attempts to climb up the bob-stay back to the ship. He rolls a 39 for a successful climb setting hit DC to seven. Rolls d20 plus one for strength and subtracts five for being restrained, 8+1-5=4 he fails and gravity CP on him remains at 6 CP (restrained). As restrained Draper can’t move. He’s stuck on the bob-stay with Barnes.

Round 4: Gravity always wins initiative and Draper ends us with 3 CP (lucky for him) for a total of 9 CP due to his remaining 6 CP (restrained, -5 as before) and Barnes gets 7 CP for a total 12 CP. Barnes is incapacitated and falls.

However, the DM rules that Barnes can attempt to grapple Draper on the way down if he wins initiative. Which he does, maintaining his initiative streak. Drapers grapple DC is reduced by 5 as the DM rules hanging from the ropes is the equivalent of one-handed status from normal grappling which makes Drapers grappled DC to be 7. Barnes rolls a 19+1=20 and get five grapple CP on Draper. Five CP plus Drapers nine CP put him at 14 CP, he’s incapacitated. Draper loses his grip and they both plunge into the sea.

Round 5: Draper and Barnes land in the sea. Both are no longer hanging so their CP from gravity set to zero but, Barnes still has 5 CP on Draper. And gravity always wins initiative and hits. The DM rules that since Barnes is not attempting to tread water so he encumbers Draper (adding +6 to gravity DC). Note that another option for this situation would be to add Barne’s gravity CP to Draper. The GM rolls d4+1 for four points totaling to 9 CP. Draper is restrained, he can only tread water.

Draper win initiative and rolls decides to fight Barnes to disentangle himself from Barnes. Draper rolls against Barnes’s Grapple DC of 12 and gets 17+1-5=13 which hits barely. He rolls 6+1=7 CP and puts them five into breaking Barnes’s hold and two into reducing gravity’s CP to 2. Gravity still has Draper grabbed but, he has the lifering and gets 8 free CP reducing his CP to zero.

Now, no longer holding onto Draper, the DM rules Barnes must now feel the effects of gravity and rolls a maximum of five CP. Barnes is grappled (grappled, -2). Barnes loses interest in grappling Draper and tries to tread water. He has no especially swim skill so gains no bonus. He rolls a d20 plus one for strength and gets a 4+1 =5 and fails. He remains in the grappled condition (-2) at 5 CP.

Round 6: Draper and Barnes are now separated. Gravity has its effect. Draper gets 5 CP (grappled, -2). Barnes gets 4 CP for a total 9 CP (restrained, -5).

Barnes wins initiative and treads water. He rolls a d20 for 12+1-5=8 and misses. Gravity adds 3 to Barnes leaving him at 12 CP he has been incapacitated by the waves and sinks.

Draper rolls a d20 and add one for strength and gets 16+1-2 =15 and hits (he only needed 1 with the lifering). Draper then gets 4+1+8 =13 CP which he uses to set his CP to zero. He swims away from Barnes.

Round 7: Gravity rolls well against Barns for 5 more, putting him at 17 CP (still incapacitated) and poorly on Draper for 2 CP, putting him at 4 CP (grappled, -2).

Draper win initiative and rolls a 13+1-2=12 a hit. He rolls d8+1 and get 4+1=5 which he applies to swimming. CP on him are now zero he can continue to swim normally.

The special rule for swimming is that being incapacitated (see below) causes a person to sink but, they can still attack as restrained at minus five. Barnes rolls a 14+1-5=10 and hits, but, then rolls 5+1 =6 CP. He subtracts the 6 CP from gravity’s 17 CP to get 11CP which is still incapacitated. He continues to sink.  At this point begin enforcing whatever the effects of drowning are in the system you choose. It looks like Davy Jone’s locker is the likely place for old Mad Dog Barnes. But, depending on further rolls and the drowning system chosen, he might be able to struggle to the surface eventually.

I don’t have it completely worked out yet. There is plenty of room for debate about: the Grapple DC of gravity; the grapple damage of gravity in air and water; when gravity should take effect in a round; what modifiers to use; if a person is holding up another against gravity should they also get the CP of the person they are holding, etc. But, I think Dungeon Grappling’s control point approach nicely fits this situation and adds drama.

So, as a final example, I think Douglas Cole’s approach in Dungeon Grappling goes beyond useful and into inspirational. And, can easily be added to many existing rule sets without adding much complication or confusion on how mechanics work. Check it out!

Below are some specific rules and modifier tables.


  • While climbing, tightrope walking, or swimming, at attacks for damage are at +5 to defenders AC (using descending AC).
  • In water grappling rolls can continue while sinking (using restrained modifiers) for however many rounds a character can survive without air.
  • If climbing or tightrope walking, falling eliminates all graivty CP on the character but, character is no longer in contact with climbing surface or rope.
  • Tightrope walking uses dexterity bonus as a modifier instead of strength.
  • Tightrope walking limited to 20 degrees or less – otherwise treated as climbing.
  • Tightrope walking has no modifier for using both arms and legs – treat that situation as climbing.
  • If armored and encumbered use both modifiers.
  • Rope don’t confer any bonus to climbing a surface but, being grip-able do confer an advantage when climbing the rope directly.
  • Characters roped together are automatically considered to be grabbing one another with 1 CP. That one stays in place unless the rope is severed or untied.
  • A climbing character who is roped to a solid object for safety does not fall when immobilized by gravity but, stays grabbed at the end of the rope.
  • For speeds of climbing and swimming use the values of whatever system is being use. I recommend the rates used in the AD&D Wilderness Survival Guide. A place to look for tightrope walking speeds is the 2rd Edition The Complete Thief’s Handbook.
  • An alternative method of climbing movement is to map the route to be climbed, divide the route into critical nodes and require one grappling roll (or multiple rolls if difficult) per critical node.


Table 1 — The Monster of Gravity

Grapple DC: 10
Attacks: 1
Grappling Damage: See table 2
Grapple Attack Roll: Automatic
Control Maximum: NA
Condition Thresholds: NA but, always wins initiative.


Table 2 — The Monster of Gravity

 Size  Space Land Base Grappling Damage In water Base Grappling Damage
Fine ½ by ½ ft. × ¼ 1 0
Diminutive 1 by 1 ft. × 1/3 1d2 1
Tiny 2 ½ by 2 ½ ft. × ½ 1d4 1d2
Small  5 by 5 ft. × ¾ 1d6+1 1d3+1
Medium 5 by 5 ft. × 1 1d8+2 1d4+1
Large 10 by 10 ft. × 1.5 2d6+4 1d6+2
Huge  15 by 15 ft. × 2 2d8+8 1d8+4
Gargantuan 20 by 20 ft. × 3 3d8+12 3d4+4
Colossal 30 by 30 ft. or larger × 4 4d8+16 2d8

Note: Magical Creatures can negate these effects as desire: either automatically or through some creature specific modifier/multiplier.

Table 3 — Climbing Modifiers


Climb Modifiers
Successful Climb Roll -3 gravity DC
Critical Success Climb Roll -3 gravity DC & double character grapple damage
Climbing Tools (crampons, special shoes, spikes, etc. but, not ropes) -3 gravity DC+ additional grapple damage equal to gravity base damage (e.g. +2 for medium).
Arms & Legs -3 gravity DC
Armored +3 gravity DC
Encumbered +3 gravity DC
Glass surface +9 to gravity DC
Ice +6 to gravity DC
Smooth surface (stucco or similar) +4 to gravity DC
Medium surface (castle wall, dungeon wall) Normal DC
Rough Surface (typical cliff) -4 gravity DC
Very Rough Surface (with many handholds) -6 gravity DC
Rope -3 gravity DC
up to 45 degree slope -5 gravity DC
up to 60 Degree slope -3 gravity DC
Vertical Normal DC
Inverted up to 45 degrees +3 gravity DC
Inverted up to 60 degree slope +5 gravity DC
Inverted up to 90 degrees +7 gravity DC
Grabbed 1/2 climb rate
Grappled 1/4 climb rate
Restrained can’t move
Incapacitated falls
Table 4 — Swimming Modifiers
Swim/float Modifiers
Successful Swim Roll -3 gravity DC
Critical Success Swim Roll -3 gravity DC & double character grapple damage
Flippers -3 gravity DC+ additional grapple damage equal to gravity base damage (e.g. +1 for medium).
Arms & Legs -3 gravity DC
Life Jacket or other flotation device -9 gravity DC + 8 CP if successful
Clothed +3 gravity DC
Armored +6 gravity DC
Encumbered +6 gravity DC
Smooth Water Normal
Choppy +3 gravity DC
Waves +6 gravity DC
Large Waves +9 gravity DC
Grabbed 1/2 swim rate
Grappled 1/4 swim rate
Restrained can’t swim, must tread water
Incapacitated Sinks  (but, can still attack as restrained)


Table 5 – Tightrope Walking Modifiers

Tightrope Modifiers
Successful Acrobatics Roll -3 gravity DC
Critical Success Acrobatics Roll -3 gravity DC & double character grapple damage
Barefoot -3 gravity DC
Running +6 gravity DC
Armored +3 gravity DC
Encumbered +6 gravity DC
Calm wind Normal
Breeze +3 gravity DC
Stiff Breeze +6 gravity DC
Storm +9 gravity DC
Grabbed 1/2 move rate
Grappled 1/4 move rate
Restrained can’t move, must stop
Incapacitated falls








  • castaliahouse says:

    Fantastic! I love this sort of insanely detailed esoterica. Great stuff!

  • For what it’s worth, Brian, I endorse this one. The concept of gravity getting the first attack, so you always have to worry about not falling first, and only AFTER you have secured your grip can you fight an attacker or move about the (precarious) landscape is *exactly* the sort of tension control points are meant to bring to the table. That you can model both active wrestling and fighting to remain balanced or maintain your grip while dangling from the proverbial ledge is now more than just “make a single die roll against climbing.” Now there’s uncertainty, and it’s the *risk* that provides value (or as my finance instructor once said, the value of a stock option with zero uncertainty is zero).

    • Brian Renninger says:

      Thanks, I’m glad you like it. I thought it might be over complicated or a bit of a step too far. I still think there might be something to simplify the two-steps of making a skill check and then a hit roll but, conceptually it seems really appeal to me.

      • There are two primary mechanics for tossing out damage in DnD, and control points are just another type of damage. The first is the attack roll, which if successful, is followed by an effect roll. The other is the *saving throw*, which is used when an attack automatically hits, but you can save to either completely or partially negate the effect.

        That seems to be the operative mode here. Gravity *always* hits and rolls damage, which is variable based on size (that was well done, by the way). It is thus incumbent upon the character to make a saving throw (which doesn’t ever consume an action) to avoid gravity’s full damage. If they feel they don’t need to mitigate (attack to counter gravity’s control points), they can do what they wish. If they do feel that tension, they have to reduce gravity’s drag on them by grappling a rope, wall, cliff, or the water, depending on their environment.

        If you wanted to do away with even more rolls, just simply apply the appropriate variable control damage for gravity’s pull to every creature so dangling, either all at once, when the round first starts, or as each creature’s turn comes up (that might be easiest, since it avoids the GM having to sit there making fifty damage rolls in a big combat all at once; you can just do it on each critter’s turn).

        So I agree, you can cut down on the number of rolls. Either just let the character make a saving throw for half damage, or simply roll damage each turn, and the character better have have the right STR for the job.

        Note that for Swords and Wizardry, you’ll want to decide what “can lift their own body weight” means for different size creatures. For humans/medium-sized, they’ll be doing 1d8 and suffering the same, but bonuses from STR are +1 to +3 for fighters only. So with gravity at 1d8+2, it means that (for example) thieves will always be losing to gravity, while only fighters with STR 16-18 can break even or win. For fifth edition, saying STR 14 (the average character’s STR, with a +2 bonus) is “can lift own weight” and balancing that against the 1d8+2 you have seems about perfect to me.

        • Brian Renninger says:

          Excellent point on the strength question. I was thinking in terms of most people can barely lift their own weight so only the strongest should have a clear advantage over gravity. But, even a +1 is extraordinary strength. So maybe dial medium back to 1d8+1 and the others in similar fashion. But, thieves also get a bonus for skill so that mitigates lack of strength a bit. Hm.

          One option is rather than treat skill as modifying DC skill could be the saving throw to the gravity damage. In that case players would accrue gravity CP points and halve them with a successful skill roll.

          • Yes, that’s definitely an approach to take. One other consideration is that in Basic D&D r AD&D the Thief’s climb walls skill should factor in as a BENEFIT, always. So a conversion of a percentile-based score to some sort of skill bonus or control point bonus should factor in here.

          • Brian Renninger says:

            The idea of using a climb roll like a saving throw is growing on me. Halving CP is a big advantage. Possibly maybe even have automatic halve if a character has climb and all CP (gained that round) with a successful skill check. That way a thief could really move around while other characters must necessarily be much more ginger.

  • Samwise7RPG says:

    Thanks for this. I don’t think I’ve ever written something to detailed and exact. I’m a bit overwhelmed with it! hehe. Nice work for the #MakeSomethinDammitRPGChallenge

    • Brian Renninger says:

      Thanks, and you are welcome. Douglas Cole inspired me. I’m going to prepare a third version (this one is the second draft)based on his comments here. When I get it done, I’ll share it.

    • Brian did a great job of taking something foundational (the concept of grip strength and restraint) and broadening its appeal in a way that adheres to most of my “rules for grappling rules,” which really ought to be extended to “rules for game writing.”

      He’s (a) using what’s there, in that he’s taking the exact same principles and resolution pathways that are used for wrestling between creatures and applying them in an intuitive way for something that is beyond the initial scope of the rules, he’s (b) minimizing bookkeeping where possible, in that you really only need to keep track of the resultant control points, and not where they come from, to understand what’s happening to the actors involved, and (c) making it *interesting*, in that you can have things happen with this system that happen as emergent behavior.

      You might have a few good grapple rolls by gravity, and both combatants have to spend a few turns doing nothing but clinging to their rock walls. And because both gravity and the PCs rolls are random, you really never know when you’ll have a moment to chuck that dagger at your also-dangling foe. In most games, you make your climb check and then move on. Not so with Brian’s adaptation.

      The possibilities here really are very cool.

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