Does a roll of 50 hit on a 100 percentile check?

[alex1g]

Does a roll of 50 hit on a 100 percentile check? Player is saying that I have to roll 51. Never heard of that.

[AnimeTheCat]

What is this in reference to? A d100 ranges from 1 to 100 so 1-50% is the first half and 51-100% is the second half, if that's what you're asking.

[gooddragon1]

Does a roll of 50 hit on a 100 percentile check? Player is saying that I have to roll 51. Never heard of that.

No. The reason is that there are 50 chances from 1-50 and 50 chances from 51 to 100. It's similar to how a 1d4 has 50% chance of rolling a 1 or 2 and 50% chance of rolling a 3 or 4.

Semi Swordsaged.

[KillianHawkeye]

Well it depends on how it is phrased. If you have a 50% chance to miss, then rolling a 50 means you missed because it rolled in the {0 -- 50} range. If you have a 50% chance to succeed on some action that's purely chance-based, then rolling a 50 means you succeeded for the same reason.

Whenever you roll percentile dice in D&D to determine the occurrence of a random event (as opposed to rolling for results based on a table), you always want to roll equal to or lower than the target number if you want the "% chance to X" event to happen, or higher than the target number if you want to avoid it.

[Crake]

Well it depends on how it is phrased. If you have a 50% chance to miss, then rolling a 50 means you missed because it rolled in the {0 -- 50} range. If you have a 50% chance to succeed on some action that's purely chance-based, then rolling a 50 means you succeeded for the same reason.

Whenever you roll percentile dice in D&D to determine the occurrence of a random event (as opposed to rolling for results based on a table), you always want to roll equal to or lower than the target number if you want the "% chance to X" event to happen, or higher than the target number if you want to avoid it.

Generally when a roll is "% chance to X" we define the percentage range before the roll, rather than assuming some kind of convention based around the wording. There's no logical difference between a 50% chance to fail or a 50% chance to succeed, assuming there are no intermediate positions, so saying "this ability says 50% chance to succeed, therefore 1-50 is a success, while this ability says 50% chance to fail, therefore 1-50 is a fail" just gets confusing all too quickly.

Just declare what the ranges are before you roll "1-20 is a miss" or "81+ misses" is mechanically identical, as there is no set rules for how to handle percentage chances in dnd, unless the ranges are already determined like in confusion rolls and teleport mishap chances.

[Nibbens]

To avoid this, I often ask my PCs if they want the beneficial thing (for them) to to happen - and name the exact numbers they need - on a low or high roll.

So, if there's a 20 percent miss chance, I ask if they want 1-20 to be the miss or 80-100 (or 81-100 to be more precise) to be the miss.

This way, everyone is aware of exactly the numbers needed. It takes a few seconds longer, but it adds more tension to the situation, because now the PCs feel like they're gambling and have a more direct influence of wether or not they succeed or fail.

[KillianHawkeye]

Generally when a roll is "% chance to X" we define the percentage range before the roll, rather than assuming some kind of convention based around the wording. There's no logical difference between a 50% chance to fail or a 50% chance to succeed, assuming there are no intermediate positions, so saying "this ability says 50% chance to succeed, therefore 1-50 is a success, while this ability says 50% chance to fail, therefore 1-50 is a fail" just gets confusing all too quickly.

Just declare what the ranges are before you roll "1-20 is a miss" or "81+ misses" is mechanically identical, as there is no set rules for how to handle percentage chances in dnd, unless the ranges are already determined like in confusion rolls and teleport mishap chances.

You're right that you can define your own success or failure ranges if you really want to, and that in practicality it doesn't matter when the chance is 50/50.

Hmm... on further investigation, it appears I may have misremembered a rolling convention for percentile dice (or perhaps a rule from a different game) as a rule. However, I don't see what the big difference is between "following what the ability says" and "just decide for yourself what the success and failure range is". Either way, you have to take a mental step to evaluate or decide the outcome range.

If anything, deciding for yourself takes longer because you need to weigh whether or not you want the roll to succeed or whether you prefer to roll high or low or whatever criteria you're using to make that decision. Whereas with my way, if I read "20% chance to miss" I simply roll the d% and compare to 20 and know right away if "chance to X" happened or didn't happen. It's a simple "If Y, then X" process with no decision-making whatsoever.

So, since I couldn't find it in a book, I guess it isn't a rule per se. I don't know where I picked it up. It's just the faster, more efficient way of rolling percentile dice. In the end, whenever you roll to determine the outcome of a binary "yes or no" chance, you have to evaluate whether you're rolling for "chance to X" or "chance to Not X" each time anyway. Why not have a standardized method instead of having to complicate it every time?

[Elkad]

Only if you rule 00 = zero instead of 100.

Otherwise the rest of the thread is right.

For coinflip odds like 50% miss chance, I just grab any random die and say "odd hits, even misses"

Most of my players like to pick a number to stabilize on before they roll their d10. "I need a 7", rolls a 1, "bad words!"

[BearonVonMu]

I second Elkad's general method for rolling 50% miss chance, but do it by just asking the PC "do you want high or low?", giving them the result favorable to them if they called it correctly.
I'll also frequently toss a d6 for that roll, since it takes slightly less brainpower to parse the results and I'm a lazy game master like that.