Game Basics, Part 3

Posted on July 19, 2017

Passive Checks and Asynchronous Design

Before I move on to other check situations, a bit about a design decision. With this initial draft of rules I’m going to try out making as many dice rolls as possible player facing. The gamemaster will by default largely only roll dice for two reasons: to generate content or game world behavior meant to inspire emergent gameplay, and to make one of the GM facing checks, which are limited to situations where not knowing the results (or, when possible, that a check is even taking place as opposed to a content/behavior roll) will heighten the surprise, tension, or drama of the situation.

As a general rule, NPCs, Beasts, spirits, monsters (a creature which is the result of a long-term non-Powers Below magical influence on natural evolution), and natural animals will have DCs as a core part of their stats where in 5e an NPC would have a roll bonus. This means, among other things, that player characters will make Defense rolls rather than NPCs attacking the PCs making attack rolls. Most NPC DCs will be determined in a typical d20 system manner--the passive check score, which for this game will be:

10 + 1st Ability score modifier + 2nd ability modifier + NPC’s threat class + all other applicable modifiers

If the character has advantage on the check, add 5. For disadvantage, subtract 5.


Sometimes one character’s or monster’s efforts are directly opposed to another’s. This can occur when both of them are trying to do the same thing and only one can succeed, such as attempting to snatch up an item of importance that has fallen on the floor. This situation also applies when one of them is trying to prevent the other one from accomplishing a goal—for example, when a character desperately hold closed a Beast is trying to push through. In situations like these, the outcome is determined by a special form of check, called a contest.

When a PC is taking part, contests are not that different than other ability checks. The DC of the check is determined by the NPC’s most relevant score. The player makes their check as normal, and the Gamemaster compares it to the NPC’s score as determined above. If the PC’s result is higher, they either succeeds at their action or prevents the other NPC from succeeding, as circumstances dictate. If the PC does not exceed the DC, they either fail their action or the NPC succeeds.

If the PC ties the DC, the situation remains the same as it was before the contest. Thus, one contestant might win the contest by default. If two characters tie in a contest to snatch a ring off the floor, neither character grabs it. In a contest between a Beast trying to open a door and an character trying to keep the door closed, a tie means that the door remains shut.

If two PCs are engaged in a contest, each rolls a check as normal. The winner is determined as above by comparing the two check results.

If two NPCs are engaged in a contest, simply compare their most relevant scores, and the one with the higher score wins without some sort of intervention by a PC. If they are tied, subtract each NPC’s threat rating from their score, and instead roll the proficiency die tied to that rating for each NPC, adding it back into the previously modified score. If this still results in a tie, treat as a tie as described above.

Intermediate Rule: Depending on the type of contest, margins of success may apply.