I'd be interested to see how much actual variation comes from the most popular methods of character creation. And whether that ratio has changed much by, say, level 8 when everyone has had a chance at a minimum of two ASIs.
Sure! Let me fire up Excel right quick. Full probability curves for the 4d6 Drop Lowest method have already been generated by Jasper Flick, and
you can find them here. But that's not very helpful for comparison, since none of the other methods have any probability at all. So for the sake of this exercise, I'll use mathematical averages to measure and compare that "actual variation."
Standard Array
The sum of (15, 14, 13, 12, 10, 8) is 72, and the average for any one ability score is 12.00.
4d6 Drop Lowest
Across 130,000 iterations in Microsoft Excel, the average for any one ability score is 12.24.
(Why did I stop at 130,000? I got tired of holding down the Page-Down key.)
Point Buy
There are only
65 possible combinations of stats that can be "legally" generated using the Point Buy rules as-written in the PHB.
The "best" set you can pick is (13, 13, 13, 12, 12, 12) which returns an average of 12.50.
The "worst" set you can pick is (15, 15, 15, 8, 8, 8) which returns an average of 11.50.
And if you average all 65 sets together, the average of any one ability score is 12.05.
I thought it was interesting that the further your selected numbers are from the mathematical average (12.05), the
worse they are overall as a set. Which makes sense; that's how the law of averages works but not many players realize that.
3d6 Straight Roll
Across 130,000 iterations in Microsoft Excel, the average for any one ability score is 10.50.
(This method isn't in the PHB, and it's incredibly unpopular among 5E players. I only include it here because I found it amusing.)
CONCLUSION:
The amount of variation between the most popular methods of character creation are as follows. On the average:
- The highest stats can be chosen with the Point Buy method.
- The lowest stats can be chosen with the Point Buy method.
- The most reliable stats are selected from the Standard Array, which is a single set that cannot change.
- The 4d6 Drop Lowest method generates better stats than the Standard Array, but is otherwise in the middle when compared to all other methods. Thus, the only real reason to choose (or oppose) the 4d6 Drop Lowest method--mathematically-speaking--is the reliability: whether you wish to allow (or avoid) random numbers during character generation.
CONSIDERING ASIs
Most races grant a +2 to one score and a +1 to another, which is an average of +0.50 to each.
Mountain dwarves, half-elves, and a handful of others grant +2 to two ability scores, which is an average of +0.67 to each.
Humans have the best racial ASIs, at +1 to each ability score.
Feats add a +0 or +1, depending, and they're an optional rule besides, so for the purpose of this exercise we will assume they aren't used.
At 4th level, the character gains a net of +2 to their ability scores, or +0.33.
At 8th level, the character gains a net of +2 to their ability scores again, another +0.33.
These ASIs are applied equally after stats are generated...in other words, Humans still get +1 to each ability score whether you used the Standard Array or Point Buy.
Now.
Just for fun, let's build some characters!
Using the average result of 4d6 Drop Lowest (12) for all stats:
Your stats are 12, 12, 12, 12, 12, and 12.
Choose Human, they are now 13, 13, 13, 13, 13, and 13.
At 8th level, your stats will be 14, 14, 14, 14, 13, and 13...an average of 13.67.
Your total ability score bonus is +10 (+2, +2, +2, +2, +1, and +1).
The highest stats possible, on average, at 8th level, will be:
Use the Point Buy method, and choose 13, 13, 13, 12, 12, 12.
Choose Human, your stats are now 14, 14, 14, 13, 13, 13.
At 8th level, your stats will be 16, 16, 14, 13, 13, and 13....an average of 14.17.
Your total ability score bonus is +11 (+3, +3, +2, +1, +1, and +1).
The worst stats possible, on average, at 8th level, will be:
Use the Point Buy method, and choose 15, 15, 15, 8, 8, 8.
Choose any race that gives +2/+1 ASI, your stats are now 15, 15, 15, 10, 9, 8.
At 8th level, your stats will be 16, 15, 15, 11, 9, and 9...an average of 12.50.
Your total ability score bonus is +5 (+3, +2, +2, +0, -1, and -1).
And if you really want to scrape the bottom of the toilet bowl with your stats, you could use the optional rules for Feats and then pick any two feats that lack ASIs. Your stats would be 15, 15, 15, 10, 9, and 8, with a total bonus of +4.