Does taking 10 increase the time it takes to perform an action?

My GM says that, when you take 20, your action takes 20x the normal time, with which I agree. However, they also claim that it takes 10x the listed time if I choose to take 10. I explicitly asked whether it was a house rule and was directed to p.86 of the Core rulebook, but here is what it says:

Taking 10: When your character is not in immediate danger or distracted, you may choose to take 10. Instead of rolling 1d20 for the skill check, calculate your result as if you had rolled a 10. For many routine tasks, taking 10 makes them automatically successful. Distractions or threats (such as combat) make it impossible for a character to take 10. In most cases, taking 10 is purely a safety measure—you know (or expect) that an average roll will succeed but fear that a poor roll might fail, so you elect to settle for the average roll (a 10). Taking 10 is especially useful in situations where a particularly high roll wouldn’t help.

They quoted this whole section and accompanied it with the following phrase: "in extention there is a time delay variable depending on circumstances".

Honestly, I can't see anything about this delay, so I've searched the whole book for the following keywords:

1. "Delay": got information about delaying your actions and spells like Delay Poison
2. "Taking 10", "Take 10": found the related section and also some class abilities' descriptions and a few other minor references.

My GM is very experienced; they have played this game since at least AD&D2e. Thus, I believe that they know the rules very well. Before I continue pestering them about this issue, I want to make sure that I myself understand things correctly.

Interestingly enough, if you actually rolled 20 times instead of taking 20, your odds of getting a natural 20 would only be ~64.14%; it would take about 45 rolls to have a ~90% chance of scoring a natural 20. If you rolled 10 times instead of taking 10, though, your odds of never scoring a natural 10 or higher would be about 0.34%. This means that taking 10 is almost never worth it under my GM's ruling.

Are there any rules about Taking 10 that explicitly increase the time it takes to make a check? Are there any indications other than Rule 0 that tell GMs to adjust the time it takes to perform a skill check based on circumstances?

• If you are not in danger, not in hurry, not distracted, why does it matter at all? Nov 8 '21 at 13:47
• @Mołot Because time actually does matter. Nov 8 '21 at 16:50
• @Tal No, in 3.5e taking 10 did not take more time. Taking 10 is and was a shortcut for "there's no pressure, average is enough, so why bother rolling?" and takes the same time as the single roll it replaces. Taking 20 is a shortcut for rolling over and over and over again for repeated attempts until you get a 20, and takes the same time as the average number of rolls it would replace. Nov 8 '21 at 19:10
• @Molot There are plenty of cases where it matters. You might be in a hurry. You might be in combat but have an ability that allows you to Take 10 anyway. You might be swimming/hovering and have to make a skill check every round not to sink/fall. Nov 9 '21 at 10:30
• This is one of the few things that I feel Matt Mercer consistently gets wrong. A player will ask "can I see X?" and he'll ask for a perception check, even in non-stressful situations where what they're looking at is something that should be obvious and clearly visible. Nov 9 '21 at 16:06

No such rule exists, you can read the entire rules for Taking 10 on page 86 of the core rulebook:

When your character is not in immediate danger or distracted, you may choose to take 10. Instead of rolling 1d20 for the skill check, calculate your result as if you had rolled a 10. For many routine tasks, taking 10 makes them automatically successful. Distractions or threats (such as combat) make it impossible for a character to take 10. In most cases, taking 10 is purely a safety measure—you know (or expect) that an average roll will succeed but fear that a poor roll might fail, so you elect to settle for the average roll (a 10). Taking 10 is especially useful in situations where a particularly high roll wouldn’t help.

For reference, the rules for Taking 20 do include a 20x increase in time:

When you have plenty of time, you are faced with no threats or distractions, and the skill being attempted carries no penalties for failure, you can take 20. In other words, if you a d20 roll enough times, eventually you will get a 20. Instead of rolling 1d20 for the skill check, just calculate your result as if you had rolled a 20.

Taking 20 means you are trying until you get it right, and it assumes that you fail many times before succeeding. Taking 20 takes 20 times as long as making a single check would take (usually 2 minutes for a skill that takes 1 round or less to perform).

• Nov 8 '21 at 2:55
• If you go by "it takes 20x because on average it takes 20 rolls to expect a 20", then taking 10 should be 2x, or "enough extra that you can't do it while threatened". Nov 8 '21 at 10:06
• But they explicitly say "Taking 20 takes 20 times as long". If they wanted taking 10 to be 2x, they'd say "Taking 10 takes twice as long". Nov 11 '21 at 6:03
• Keep in mind the odds of rolling 10 in 10 rolls are much much higher than the odds of getting a 20 in 20 rolls.: 1-(19/20)^20 = 64% < 1-(9/20)^10 = 99.97% Nov 11 '21 at 6:47

No

your GM's ruling was wrong. There is no time increase when "Taking 10". Taking 10 is not about "doing something slowly & carefully", but about doing something in a routine way without distraction. I.e. you're not "doing your best" (Taking 20) but "doing your average" (Taking 10). It is taking the statistical noise out of your efforts, like a cook who's cutting vegetables: All the slices end up the same size instead of big slices (rolled a 1) and thin slices (rolled 20).

If the rules on Taking 10 aren't enough to convince your GM, point him to feats such as Perfect Center:

Benefit: You can take 10 on any skill check or concentration check, even if it is not normally allowed due to strenuous circumstances.

Feats like this make it perfectly clear that it cannot mean you need more time: You are merely able to focus and ignore distractions enough to do your routine on skills even while you're bleeding profusely, carrying an unconscious ally, while the ship is sinking, and the delayed Fireball is about to detonate.

There is a clarification from Sean K Reynolds, one of the people who wrote the core rulebook:

Taking 10 requires only as much time as making one check.