View Full Version : Original System A Different Kind of D20 Roll

2017-03-02, 04:48 PM
Okay, so I'm currently trying to stitch together two of my favourite RPGs into a single system, since both myself and my players love different parts of both of them. When faced with choosing a kind of die roll, D20 vs D100, I eventually picked D20 since it's simpler and more familiar, but at the same time, we wanted to use some of the features of the D100 system. This is the mechanic summed up as briefly as possible:

When a player wants to make a test of any kind, they roll a D20.
The result on the roll is compared to a target value which depends on various factors.
If you get less than or equal to the value, you succeed at whatever it is you're doing, and get one 'Assurance'. If you go over, you've failed, and you get one 'Mishap'.
You can get additional Assurances or Mishaps depending on how big the difference between the target value and the die roll is.

I currently have two different ways of doing Assurance/Mishap resolution:

You take the difference between the target value and the result on the die roll and halve it, ignoring decimals. You get that many additional Assurances or Mishaps.
You take the difference between the target value and the result on the die roll and roll that many D6s. For every 4+, you get one more Assurance or Mishap.

Not sure which of these to use, or even if I should modify the second one further.

Core Mechanic Maths Stuff:
Base Value + Characteristic Modifier + Situational Modifiers + Skill Modifier (if it's applicable)

Base value is usually 8, though that's subject to change depending on A) if it proves to be too high or too low, and B) in-game circumstances, but the latter is very rare so you can count on it almost always being 8.
Your Characteristic Modifier follows standard D&D ability score modifiers. Average people have about 10 or 11, your characters will usually have more in at least one characteristic.
Situational Modifiers are things like the quality of tools you're using, environmental conditions like light and weather, how much pressure you're under, how specific the task you want to do is, if you decide to take longer and be more careful, and many more. These affect the Difficulty of the task: the more you do to prepare, the easier tasks get. Difficulty ranges from Trivial (+8) to Gruelling (-10).
Skill Modifier is just the bonus given if you have training in the skill related to the task you're doing. This comes in 5 flavours: -4, +0, +2, +4, and +6.

Assurances and Mishaps
Assurances and Mishaps are what allow you to quantify just how well you've done or how badly you messed up. More of either results in more spectacular things occurring eg: getting 5 Assurances on a test to charm someone will increase their disposition towards you much more than 1 Assurance would; they might even reveal something that would otherwise be hidden from you.

In combat, Assurances also determine how many times you hit someone with a ranged weapon if you're firing on semi or full auto, or a melee weapon if you're attempting a Rapid or Chain attack. Successfully negating an enemy's attack, whether by Dodging or Parrying it, requires you to get more Assurances than they did on their attack. Otherwise, you'll either fail to negate it entirely, or still suffer some hits. Parrying also offers the chance to counter attack if you have the right feats/talents/whatever.

Thoughts? Critique? Should I scrap the whole thing and try something else?