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The Only D&D Subsystem You Need - The Ability Check

by Mike on 14 July 2022

A lot of D&D books include new systems for all sorts of things including dealing with avalanches, piloting boats, running a performance, or managing a tavern. As DMs, we're often tempted to build our own new subsystems for situations in the game.

We need not, however, because we already have a system in place able to handle just about situation we face:

The ability check.

The humble ability check is a wonderfully simple mechanic useful for just about any situation in the game. Nearly every action a character takes in the game can, when needed, be represented by an ability check. If a relevant skill helps in the action and they happen to be trained, they can add their proficiency bonus. As DMs, we have the tools of advantage and disadvantage to further shift the situation depending on the circumstances.

Most importantly, the ability check is an excellent improvisational tool. We don't know what the player is going to think up but, whatever it is, we're likely to figure out how to tie it to an ability check if the success or failure of the action is in question.

Now if something is happening to the character instead of the other way around, we have another tool for this: the saving throw. Like an ability check, it's a great tool to improvise the success or failure of an external force affecting a character. Like the ability check DMs can impose advantage or disadvantage if the circumstances require it, although such impositions on a saving throw are rare.

During our prep we may be tempted to build complicated networks of checks and actions to suit a situation or environment but such flow-charts often fall apart in play. Often such networks of checks require anticipating how characters face problems and that's not our job. Our job is to build situations and let the characters choose their approach.

It's far more useful to spend our time understanding how complicated situation works within the game's world and fiction so we're ready to improvise ability checks and saving throws as needed.

The next time you're tempted to design a new sub-system around some complicated situation, focus instead on the situation in the world. How does it work in the fiction? Then let the characters choose their approach and use the deviously simple ability check and saving throw to adjudicate the results.

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