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:
- "Delay": got information about delaying your actions and spells like Delay Poison
- "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?