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 Tell me about... Modiphius' 2d20 System!

Francis Helie

RPGnet Member
Validated User
In case people are curious here are the overview of what I have been doing.

Use the character creation, skills, Glory, personality and Passions from Pendragon.
Resolution uses the 2d20 engine. Roll 2d20 under skill. Difficulty from 1 to 5.
Calculate momentum and threat normally.
Winner is the one that rolls highest die.
Critical is ¼ of skill high result 1-2 no crit. 3-6= equal skill 7-10=2 under 11-14= 3 under. 15-18=4 under 19-20+ = 5 under
Ex. Sword 15 will have a critical on 12-15 Courtesy 9 on 8 and 9.

Momentum use.

Bonus Damage
1 R​
Each Momentum spent adds +1D6 to damage on a successful attack.

Reroll a d20 after the original roll
1 R​
The character gains 1d6 Soak per Momentum spent (maximum 4)

One weapon held by the target is knocked away and falls to the ground within Reach. This costs 2 points of Momentum if the target is holding the weapon in one hand or 3 points of Momentum if the weapon is braced or held in two hands.

Re-roll Damage
The player may re-roll any number of damage dice from the character’s current attack.

Second Wind
1 I,R​
The character recovers 1d6 point for each Momentum spent.

Secondary Target
A second target within Reach suffers half an attack’s damage (rounding up).

Swift Action
The character gains an additional Standard Action, increasing the Difficulty by one step on any skill test that action requires.

Add up to 3 Bonus dice on roll, must be used before rolling. 1 die for 1 Momentum, 3 for 2 Dice or 6 for 3 Dicel

Shield Sacrifice. 1. Sacrifice shield to avoid damage. Shield blocks 6d6


Back Off the Buddha!
Validated User
2d20 is an odd system. It’s very close to being excellent but there are just a few too many rough edges that can turn a person off that it is a bit of a gamble when introducing people to it.

My favourite iteration on balance is also Conan as it’s not too convoluted, but still feels like it has the right weight for the mechanical chassis. One caveat is that we do away with Combat dice and just treat each Combat dice as 1 damage with a. Effect for every 3 damage. We just found that by the time the system hit Conan, the CD felt like an unnecessary legacy from MC and Infinity.

Francis Helie

RPGnet Member
Validated User
OMG! That is one of the coolest ideas I have read in a long time. Basically bumps up the SFX and stunt team budgets...
Thanks we're pretty happy with it. It helps with consistency. Our main issue with Pendragon was randomness. The constant hunt for criticals broke the game for us. The odds in 2d20 is more flat if that makes sense. Glad you like the idea.

Francis Helie

RPGnet Member
Validated User
Hmm, makes a lot of sense, the high skills thing is trickier than it looks though, at least to do it to my satisfaction. Because 2d20 stats seem to work well in the range above 10, it might make sense to do something like lowering their stats by enough tens to get it under 20, then rolling that, with some benefit, like two more dice or an autosuccess for each 10 you took away. Maths is still very strange though, especially when you start spending momentum..
I do agree. Not sure if it's better to roll 2 dice under 15 and one under 10 or 2d20 vs 20 and 1d20 under 5. We've been enjoying it, but I wouldn't say it is completely baked yet. I would love to get your thoughts to make it better.


Neo•Geo Fanboy
Validated User
Yeah, the combat dice thing is a little weird IMO. I don’t think I’ve played a game that uses standard and custom dice before aside from The One Ring.


Back Off the Buddha!
Validated User
Yeah, the combat dice thing is a little weird IMO. I don’t think I’ve played a game that uses standard and custom dice before aside from The One Ring.
It was important in Infinity where CD were used to determine Effects and potentially a small increase in damage on what was otherwise fixed. In Conan, the fixed damage was removed but the result statistically was to almost make 1 CD = 1 damage. Logically I feel they should have taken this one more step and either kept CD for determining effects only or, better yet, remove CD and have Effects based on damage.

Fortunately, it’s easy to take this step as a house rule. But it is an example of just one of those rough edges which can turn people off the system before really getting into it.


Hida Without Fear
Validated User
2d20 is one of the best systems out there as its geared towards being good in play rather than being nice to read.
Every iteration has tweaked it towards evoking a feel of the setting. In Star Trek for example, during an encounter the Captain can take a 0 difficulty action to give orders. That seems random, until you twig that that action loads the Momentum pool so the characters going after the Captain have more Momentum to use to improve their tests. That directly evokes the feeling of the setting, in that the first thing that happens is the Captain gives orders.
One player described the Sniper Rifles in Mutant Chronicles being the most satisfying Sniper Rifles he's ever experienced using, they took a turn to set up the shot, but did insane damage on that shot, evoking the cinematic description of a Sniper Rifle.
John Carter instead of including an exhaustive list of talents, let players design their own with copious costings, guidelines and examples. There is a Master of Disguise talent that let you spend a momentum to vanish from a scene then later spend a momentum to replace a minion character with your character later on. It's top flight stuff.
I'd advise anyone to try playing the game with a quickstart to get a taste of it as it really brings some excellent gameplay.


Texas Gamer
Validated User
Speaking of John Carter, is there a good walkthrough of combat (or an action scene?) available online outside of the rulebook? I have the PDF but I’m still on the fence. I’ve skimmed Conan, but it’s to far on the crunchy side for what I need it for.


Miss Atomic Bomb

Welcome to your life. There's no turning back.
Staff member
RPGnet Member
Validated User
I really like the core mechanics, as well as the character creation in STA. I haven't played through full combats, though.
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