Basic Game Mechanics

The Dice

The essential die roll of the SCRPG is a high-open-ended D20. Other dice (D4, D6, D8, D12 and D20) are in limited use in the game, as well as rolls such as D2, which is typically a D4 divided by two, rounding up. These are: D2, D3, and D5. 

There are also a few abbreviations of dice rolls that will be used, such as D7 (which is 2d4-1, not D8-1). 

Granularity with the D20 is achieved with a multitude of potential modifiers including open-ended rolls, and through the assistance of the 

Open-Ended Rolls

In Combat and most other situations the D20 roll is High-Open-Ended. For an example we will use a Combat roll. In all attacks a D20 is rolled and if on that first roll the unmodified result is 20 it is considered open-ended and the combatant rolls D20 again and adds the second result to the first. If that second roll is 20, then it is also open-ended and the combatant continues to roll until rolling under 20. 

Modified Open-Ended: Through training and other potential methods, including magic, the open-ended range may be enlarged 19-20, or even 18-20. However, this modification is limited to the first and second open-ended rolls. For instance, a Character with a +1 Critical Modifier rolls a 19, and that becomes open-ended, so she rolls again for a 19, but this second 19 is not open-ended. If she had +2 Critical Modifier, then that second 19 would also become open-ended. A +3 Critical Modifier extends the 19 requirement to the third roll, while a +4 Critical Modifier returns to the first roll, opening up an 18 result being open-ended. Critical Modifiers have no theoretical limit, but achieving a +4 would be extremely rare.

There is no such thing as low open-ended rolls in the SCRPG..

Outside of Combat the Open-Ended Rolls are treated much like the combat rolls, with the second and any subsequent D20 roll of 20 allowing additional rolls.

Open-Ended Modifiers

Through intensive training, or magic, the open-ended roll requirement can be lowered from 20 to the maximum of 18. These bonuses are called explosions, and are trained one at a time to lower 19 on the first open-ended, 2nd open-ended and third open-ended. After having trained to such an extreme that the third open-ended is 19, the final explosion able to be trained is 18 on the first open-ended.

So if the Character has trained two explosions with a Maneuver, and the roll a 19 they get to roll a second D20. If that too is a 19, they get to roll a third D20. If that is a 19, they are done rolling. Now in this same instance if they had the third Explosion trained they would roll again after that third 19. A fourth Explosion would allow them to open-end the following die rolls: 18, 19, 19, 20, 20, etc. It is costly to train explosions, with only small benefit, but the eventual payoff of an 18 first explosion may be worth the effort.

Active=Opposed Rolls

Most Combat and Social Maneuver rolls and considered to be Opposed Rolls, meaning that the two primary parties involved roll D20 with all modifiers and compare their totals to find the result. As an example, in Combat Player 1 and Player 2 rolls their D20's for the Clash simultaneously, P1 = 24 while P2 = 18, a result of +6 for P1. 


In situations such as climbing a wall, the wall (most times at least!) will not be actively trying to keep the Character from climbing it, and is therefore assigned Static Difficulty. Static Difficulty may range from super easy 5 to Super difficult of 60 or more.  Anything deemed easier than a 5 is considered automatic. If the Player rolls over this difficulty level, then the action is considered a success. See Simple Maneuver below.

Non-Combat Maneuvers

There are three types of non-combat maneuvers, in respect to how they are settled mechanically and they are all open-ended D20 rolls. These are: Simple, Stepped, and Complex.

A Simple Maneuver may be any activity that the GM deems to be a basic success-fail activity, a very common example of which would be a Search roll to find a trap-door. With a Simple Maneuver a D20 is rolled, and any result which (after all modifiers) is greater than or equal to 0 is considered a Success. As an example, a Character with a Locate Hidden Skill of 9 searches for a hidden trap door which is of 24 Difficulty to find, the Player needs to roll 15 or above in order to find the door. In this instance the Player rolls a 16 (+9=25), which is >= 24 and therefore a Success.

A Stepped Maneuver is any activity that the GM deems worthy of partial success and partial failure, where a Character may succeed or fail in stages. Stepped Maneuvers are very similar to Simple Maneuvers in the D20 roll and modifiers, except that success is not as simple as is the result 0 or greater. In this case the result of the roll is taken to the Stepped Maneuver Result Chart, and in many cases the Player must roll several times before Success.

A Complex Maneuver is really a series of Simple and/or Stepped Maneuvers that leads to success or failure in a complex event. There are two major activities that will sometimes require Complex Maneuvers, Social Interactions and Crafting, but the GM may deem other connected activities as Complex Maneuvers. An example Complex Maneuver would be a Player trying to convince one person to help them, which requires another person to divulge information which requires a successful bribe to get that item, and then another bribe of a guard to get that iitem into the city, and finally when delivering the item, to make sure that that first person follows through with their promise.

The Stepped Maneuver Chart runs in two directions, high roll good and low roll good, so that the Player doesn't necessarily know whether their roll was good or bad in situations, such as social interaction, where the GM wants to retain a little secrecy with success and failure.

Group Maneuvers

In some instances Players will make Group Maneuvers. For instance, if the entire adventuring party is searching for that 24 Difficulty hidden trap door then the group would use the highest Locate Hidden Skill of the Characters in the party, with a +2 Bonus for every additional Character with a Locate Hidden Skill greater than 4 (if this were a 28 trap door, then only Characters with +8 skill would add +2 to the group roll). If the hidden door were Difficulty 5-20, then every Character is able to assist in finding  it and lends a +2. 

There are also Group Combat Maneuvers, such as Fend the Giant, which will rely upon the skills of multiple Characters in order to be a success.

Background Art by Jon Gibbons

© 2018 L. James Rice