Note: The following comes from the Sage Advice Compendium section about Ability Checks. None of this is unique to Adnati or our campaign. I’m calling it out here because these questions about ability checks come up frequently.
Attacks, Saving Throws, and Ability Checks
Are attack rolls and saving throws basically specialized ability checks?
They aren’t. It’s easy to mistake the three rolls as three faces of the same thing, because they each involve rolling a d20, adding any modifiers, and comparing the total to a Difficulty Class, and they’re all subject to advantage and disadvantage. In short, they share the same procedure for determining success or failure.
Despite this common procedure, the three rolls are separate from each other. If something in the game, like the guidance spell, affects one of them, the other two aren’t affected unless the rules specifically say so. The next few questions touch on this point again.
Critical Hits and Critical Failures
Can you get a critical hit on an ability check? For example, on a grapple attempt, does a critical win, or the highest number?
Ability checks don’t score critical hits. Attack rolls do.
Is a 1 on an ability check an automatic failure?
Rolling a 1 on an ability check or a saving throw is not an automatic failure. A 1 is an automatic miss for an attack roll.
Please see the Sage Advice Compendium section about Ability Checks for more.
Rolling a 1 on Attacks
As noted above, rolling a 1 is only an automatic failure in attack rolls. A character or creature can still succeed in their ability checks and saving throws after rolling a 1 if their additional bonuses make their modified score successful.
Additional House Rules
Some games have additional House Rules when a 1 is rolled on an attack. Some examples that we can consider include:
- Opponents in combat within melee range can use their bonus action to attack the PC or creature that rolled a 1.
- The PC or creature that rolled a 1 drops their weapon, and must use an action their next turn to pick up the weapon or use another form of attack. This has no effect when the weapon cannot be dropped, such as an attack with claws or fangs.
- The DM may have a table to determine consequences, which can range from automatic failure to dropping the weapon, injuring yourself, injuring an ally, falling prone, or giving melee opponents a bonus attack. (Rank the consequences from worse to best, and consider allowing them to add their proficiency bonus as a way for more experienced characters to have an easier chance of avoiding more severe consequences.)
- Make a Dexterity ability check against a DC 10. If they succeed, the attack still automatically fails. If they fail the Dex check, they “fumble”: they must spend their next action to recover their balance and cannot take any reactions or bonus actions until they have done so.
- Their “next action” could be the same round if they get multiple actions or attacks per round and have not yet completed all of them.
- Once they have recovered their balance, either on the same turn (if they get multiple actions) or the next, they may take any remaining actions as normal, as well as any bonus actions or reactions.
- Reroll the attack roll. If the second roll would have been a successful attack, the only consequence is an automatic failure. If it would have been a failed attack, use one of the other optional rules above.
- Roll a d20. The additional consequences other than automatic failure only apply if the roll is another 1.
Personally, I like the Dex check option (#4). It conveys the chance that the character’s equilibrium and balance have been thrown off, but more dexterous characters will have an easier time adjusting. In addition, it helps mitigate how fighters with multiple attacks are statistically more likely to roll 1s (since they’re rolling more frequently), because they are more likely to have better Dexterity scores, and because they only lose one of their multiple actions and would be more likely to recover within the same round.