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Roll D20 (homebrew system)


Loremaster Extraordinaire, at your service!
Jan 27, 2018
Hi guys!
I made a dice system to help spruce up our collaborative writing and was wondering what you guys think?

So it’s been several months since I’ve started roleplaying using dice systems on another website to give the tabletop gaming style a try. Although I don’t have a schedule free enough nor a home quiet enough to do live sessions, I only played through PbP.

The things I’ve loved about tabletop games is the storytelling and the fact that my character’s fate is decided by dice. The thing I don’t like is a GM having most of the control over the environment and how my characters should react in certain situations. So it really stifled my creative writing. It was also really slow to write because we always have to announce what we’re going to -attempt-, roll the dice, wait for the gm to tell us the result, then write it out, repeat... And all in posts of 1 paragraph long. Don’t get me started on combat -,-
It ruined the flow of reading (and writing) a story.

So I decided to try and make a system myself to better suit my needs, and hopefully will also be entertaining enough for others. I haven’t tested it out though...

My goal was to keep the focus on collaborative storytelling like we usually do on Bluemoon. But also to make sure that all the dice throwing isn’t going to slow down the flow of the story.

There is no GM/DM in this system, we just roleplay with each other like we always do. Whether it’s 1x1 or group. The D20 dice is the one that assigns stat numbers and our success rate with tasks. But damage is dealt with D4, D6, D8, D10, and D12. And we write out our own results, that way no one has to wait on each other to keep the story moving.

I’ll start with how characters are built. There are no levels or classes so you are free to make your character however you want but there are Stats. The stats are inspired by the DnD ability Scores.


Maybe we can use an xp system to increase our health over time? Or we can just leave it fixed? Either way, when the Health Bar reaches 0 that means Death. Or if you’d rather not lose your character we can call it unconscious. The modifier attached to this stat can help you with resisting things like poisons or illnesses, etc...And help reduce damage as well.


This is all about muscle power. It also determines their carrying capacity and how easy they can lift or move heavy objects. You also use this stat during Close Combat styled fighting to boost your success in fights.


This is all about your character’s Speed, Reflexes, Dodging, Sneaking, and Aiming as well. You also use this stat for Ranged Combat styled fighting, including magic. Well it depends on your magic system. If magic is mostly launched then use the Agility stat, if it’s used up close then use the Strength one. Mix and match when needed.


This is all about social interactions. Whether it’s flirting, persuasion, lying, intimidating, bartering, etc…


This is all about your character’s observation skills whether it’s based on sight, hearing, smell, etc… Or by being able to read someone’s body language; like figuring out if someone is lying to you.


Lore can influence how fast you can learn new things, or how fast you can upgrade your stats. Underneath this stat is where you gather all your knowledge of things (your lores). Your character’s education, profession (and past professions), and expertise on things go here. These Lores can give you an advantage over Lore checks.

In order to determine what your scores are you roll a D20 for each (including Health) and assign the numbers to whichever stat you like. If you don’t like the result you can roll again but only once. (it’s no fun if someone keeps rolling just to get high results). Stats cannot go higher than 20 upon assignment but they can always level up passed it if you'd like.

Example: For Mary Sue I’ve rolled the numbers...

Health = 14
Strength = 9
Agility = 13
Charisma = 3
Perception = 19
Lore = 19

Now just like in DnD you get Stat-Modifiers. In this system; these modifiers can boost your results of the dice. The reason why the mods are designed this way is because I don’t want characters to get an auto-win despite having high stat scores. Your characters can have an off-day where nothing can seem to go their way, or perhaps they are too tired, or maybe even cursed, whichever the excuse is.

1-11 = +0
12-13 = +1
14-15 = +2
16-17 = +3
18-19 = +4
20 = +5

If I refer to the modifier table this will mean that Mary Sue gets the following Mods...

Health = 14 (+2)
Strength = 9 (+0)
Agility = 13 (+1)
Charisma = 3 (+0)
Perception = 19 (+4)
Lore = 19 (+4)

The D20 dice is also used to figure out whether your character is successful at a task or not. 1-10 is always a Fail while 11-20 is always a Win.

Now let’s say Mary rolled a D20 to see if she could move a boulder that’s blocking her path. She rolls a ‘10’ which is a Fail. But we can check our Strength Stat (cause strength is used to move heavy objects) and see if we can boost our results by adding the modifier. In this case her Strength modifier is ‘+0’ so she can’t boost her results. Which means she can’t move the boulder out of the way.

There’s no critical Fails or Successes, you can write out your results however you’d like. If the players ever disagree about the written result then we’ll simply talk it out like we always do when we roleplay. : 3

Traits give your character Advantages and Disadvantages which will influence your Success rate.

Whenever you have an Advantage you can roll the D20 twice and then choose the highest result to figure out whether your character was successful at a task/conflict/obstacle or not. Same principle with a Disadvantage but you choose the Lowest score of the two dice.

To give you an idea on the types of traits your character can have, I’ve divided them in 3 categories. You can name your traits however you want as long as it's clear what they mean.

Racial Traits

They typically have anatomical or biology traits like enhanced strength, ability to fly, tough skin, enhanced speed or senses, nightvision, resistances, etc…

Social Traits

Traits that could influence the way you interact with people. Ladies man, hotheaded, sensitive soul, animal friend, actrice/actor, parental, master liar, etc...

Weakness Traits

You guessed it! All about weaknesses; allergies, phobias, disabilities, injuries, temporary traits like an illness or curse or injury, etc…

Now let’s say that Mary Sue was someone who was blessed by the Gods so she gains a Trait. Let’s call it Enhanced Strength. That means that whenever she makes a D20 roll in relation to Strength she can use her Trait as an advantage.

Let’s say Mary tries to move that that she remembered she was blessed by the Gods… She now gets to roll a D20 twice to see if she can move the boulder.

She rolled an ‘18’ and a ‘13’. Her Strength stat still has a +0 modifier so she can't add her mods to the result, so that means she can choose the highest score of ‘18’ to move the boulder. Because anything from 11-20 is a success; Tadaa, Mary Sue became a Mary Sue…

Now how do we deal with combat? Let’s have Mary fight a Troll.

Figure out first -how- you’re going to fight, and how the opponent is going to fight. In this scenario both Mary and the Troll will fight in a ‘Close Combat styled fighting’. Remember when I explained earlier that Strength is a stat you use for this type of fighting? We’ll use the mods of Strength to help boost our dice.

Mary has a Strength of 9 (+0) and our Troll will have a Strength of… *rolls* 10 (+0). So neither can use mods to boost their dice. But, Mary still has her ‘enhanced strength’ Trait that can give her an advantage; allowing her to roll the D20 twice every time she wants to use her trait.

So let’s begin our first round; Mary can roll twice, her highest score is 13 with no mods to add. The Troll rolled a 4. He doesn’t have any traits and his Strength stat doesn’t have any mods to add. So Mary wins this round. Now you figure out what the Troll’s Health is.

The Troll has…*rolls* 9 (+0).

In order to damage someone’s health you figure out what your modifiers are; using either Strength or Agility.

+0 and +1 = Use a D4 dice to deal Damage points.
+2 = D6 dice
+3 = D8 dice
+4 = D10 dice
+5 = D12 dice.

Mary’s Strength mod is +0 so she uses a D4 to deal damage to the Troll. She rolled a 2. So now the Troll’s Health went from 9 to 7. And you continue to fight till one of you is defeated.

Now remember when I said that Mary’s Health was 14 (+2)? That modifier can help reduce incoming damage. Let’s say that the Troll managed to throw a punch and rolled a 4.

Mary’s Health mod can help reduce that damage from 4 to 2. So instead of having her health reduced to 10, it was reduced to 12.

Now, I haven't figured out how you would level up your stats because when I was playing I either had someone else doing the math for me, or the game never got far enough where I got handed xp. So I have no clue how to figure that out >.>

But this is pretty much it. It's simple enough so it doesn't slow down the writing, especially since everyone is responsible for their own rolls so that'll speed up the process as well. Of course things can always be adapted depending on story and what we want. Feel free to give this system a try with your own roleplays and let me know how it went? : 3
I'm still working on a worldbuilding project myself so I don't have time to test this system out myself >.>
Last edited:


Slaver Bait
Apr 26, 2019
I think the idea of adding some game mechanics to a non-GMed game is a worthy endeavour!

But question: with no GM, how do you determine things like the HP of enemies, the difficulty of certain skill actions, etc?


Loremaster Extraordinaire, at your service!
Jan 27, 2018
Thanks :D
You would decide yourself what the stats for enemies are and such. Just like with regular roleplay you would take on a cast of characters or make up your own npc's to spruce up the story and the world. And I would do the same. You would simply discuss them in OOC (or keep it a secret). That way the flow of the story doesn't slow down too much by waiting for the GM to create enemies and figure out the difficulty levels and such. It speeds up the process.
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