D&D General Why do we Round Down???

[tommybahama]

When I get up on my scales.... I always round down too. I guess the system WAS made for me!

Anyone know where I can get a scale marked off in 20 pound increments?

 

[embee]

Anyone know where I can get a scale marked off in 20 pound increments?

The local county fair?

 

[77IM]

3.0/3.5 also had some strange rules around multiplication (x*2*2 = x*3, x*3*4=x*6, etc.). The 5e "multiclass spellcasting" rules also specify a very particular order-of-operations.

I have a new guideline for game designers: If you feel compelled to teach your players how to do basic math, your game mechanics may be too complicated for your audience.

 

[Nefermandias]

Actually, it's not that "long standing", it was just part of the general improvements made by 3e to harmonise behaviour across the system, as before that there were almost as many ways of rounding as there were rules.



I don't think I've ever seen the reason actually written down, but I think it's because of the bonus to the ability scores. They wanted only even ability scores to give you a bonus (because it's much simpler to center the curve around the number 10 than 11), and that meant rounding down. Since (as explained above), they wanted only one method for the whole game system, it's the one that was chosen.



Are there really that many ? I honestly cannot recall even one, but I'm sure you'll let us know.

3e came out 21 years ago. It's long standing. You are old.

 

[Lakesidefantasy]

I think we round down for the same reasons we only take one set of tempeorary hit points rather than adding them, or why we don't multiply modifiers and instead step them up.

I think we do this in order to apply resistance to our urges as Players to pump up the numbers. The rules of the game are complex and it is impossible to foresee problems with certain combinations of rules. We, as Players, are very good at exploring the rules and finding combinations of options that can be problematic.

I've always seen it as an unwritten rule, especially in 3rd edition, to always take the path that is less powerful. It's a kind of brake on our exuberance.

 

[Blue Orange]

I have now decided to play D&D at my next Seder. And this will be one of the Four Questions.

"In math class, we may round up or round down, depending on the dividend. Why in this edition do we only round down?"

Well, that works. You just have to tell them the problem started in 1st ed. It's a little known fact that the paladin in hell illustrated in the PHB was, in fact, Jewish, and felt disrespected by his family enough (after all, his brother was a doctor!) that he had to descend into hell and fight barbed devils to rescue the heir to the throne (who had made a deal with a devil) in order to prove himself. Finally, when he made it back, he was feted by the king, but at the banquet he was served a giant roast suckling pig and had to decline. The king, puzzled, asked,

"Why is this knight different from all other knights?"

 

[embee]

Well, that works. You just have to tell them the problem started in 1st ed. It's a little known fact that the paladin in hell illustrated in the PHB was, in fact, Jewish, and felt disrespected by his family enough (after all, his brother was a doctor!) that he had to descend into hell and fight barbed devils to rescue the heir to the throne (who had made a deal with a devil) in order to prove himself. Finally, when he made it back, he was feted by the king, but at the banquet he was served a giant roast suckling pig and had to decline. The king, puzzled, asked,

"Why is this knight different from all other knights?"

You're despicable.

 

[Shiroiken]

I always figured HP rounds up since you have 5.5 hitpoints and you take 5 points of damage, you still have >0 hitpoints and thus are still alive. Damage rounds down for the same reason.

In 2E we used to keep the half points, but they didn't count towards your active HP. It was so you gained the correct average every two levels. If you'd gain a 1d8, for example, the average would give you 4 then 5 HP over two levels. 5E makes it simpler, but I dislike the fact that it's statistically better to just take the average every time.

 

[ph0rk]

Because it is a net reduction in power for most of the roundings, with a handful of exceptions, and also simple.

 

[Charlaquin]

I'm mostly curious about 5e but tagging this General because "always round down" is such a longstanding tradition in D&D.

What's the point? Why not "always round the way your 3rd-grade math teacher taught you?"

As far as I can tell, the main effect that "always round down" has on the game is that dealing half damage benefits the defender... to the tune of 1 point of damage, 50% of the time. Well, that, plus an annoying amount of "(round up)" exceptions throughout the text.

Thoughts?

We always round in the same direction because it’s easier to just know what to do every time no matter what than to have to work out which direction to round when. Always round up would have worked just as well, but as you observe, always round down slightly benefits the defender.