Oh boy, the Wild Shape calculations... They have been so heavily debated and still get people questioning them that I think I'm developing an irrational fear of the Wild Shape rules
Back when I made the Wild Shape pages for the sheet, I couldn't find any official sources on how the Wild Shape rules work with regards to calculating some combinations of character vs. beast proficiency. I found a lot of internet discussion about it, but no official ruling. Thus, I made the sheet handle all (logical) different ways of calculation that I could think of, so everybody could use their own interpretation. Since then, there has been a little more official information on how it should be handled (in a podcast of all places...) and it has become clear that the default option is indeed the official way of doing it (I guessed correctly, yay!).
To give some explanation about the different ways:
First off, the rules are clear that you count as being proficient in Wild Shape witall things that your character is proficient AND all things the beast is proficient with. So if your character has Str saving throw proficiency and the beast has Perception proficiency, you get both those proficiencies while in Wild Shape. However, what the rules were not clear about is what ability score and what proficiency bonus you get to add to calculate the total bonus. This is where the different forms of calculations come in.
Every calculation way fills out the ability score modifier and the proficiency bonus in its own way:
Use druid's prof. bonus if druid is prof. - the default/official way is that you have your own proficiency bonus (ranging from +2 to +6) and the beast has its own proficiency bonus (mostly +2 or +3). You use the ability scores of your wild shape to calculate all proficiencies (i.e. your Int/Wis/Cha and the beast's Str/Dex/Con). If the character is proficient, use the characters proficiency bonus. If the beast is proficient, use the beast's proficiency bonus. If both are proficient, use the highest of the two proficiency bonuses.
Use druid's prof. bonus for all prof. - this alternative way of calculation is the same as the default, with the change that you always use the character's proficiency bonus, even for things that only the beast is proficient with. Some people (still) argue that this is the right way of doing things, pointing to the fact that the text "“Your game statistics are replaced by the statistics of the beast" does not specify what is included in statistics and what isn't, and because the Monster Manual does not list Proficiency Bonus, it must not be part of "statistics of the beast".
This way offers 4 variations:
Excluding attacks and expertise - the beast's proficiency bonus is used for attacks. Some creatures in the PHB, if you do the maths, seemingly have Expertise in a skill - they add double their proficiency bonus. Now there is no way to know if this is a static bonus or it is coupled with the proficiency bonus. For example, a Giant Octopus has a Dex of 13, but +5 on Stealth. It has +2 proficiency bonus, thus it is getting another +2 from somewhere. In this variant, the sheet assumes it is a static bonus. In the example of the Giant Octopus, a level 5 character would get a Stealth bonus of +6 (+1 from Dex 13, +3 from the character's proficiency bonus, and +2 from the arbitrary Giant Octopus' bonus).
Including attacks - the character's proficiency bonus is also used for the attacks in beast form. This is (was?) debated because the beast's attacks are obviously being calculated using proficiency bonus, but Jeremy Crawford has clarified on Twitter that the beast's attacks are supposed to be copied from the Monster Manual exactly without changes, as that is the intention of limiting the power of Wild Shape.
Including expertise - the character's proficiency bonus is also used for those skills that the beast seemingly has expertise with. Using our previous example, that would thus come to a total of +7 Stealth (+1 from Dex 13, +6 from twice the character's proficiency bonus).
Including attacks and expertise - the character's proficiency bonus is also used for the attacks in beast form and for those skills that the beast seemingly has expertise with.
Use creature's prof. bonus for all prof. - this alternative calculation way works the same as the previous, but uses the beast's proficiency bonus for everything. Because now there isn't any issue with 'seeming expertise', nor any debate about whether the beast's attacks should be included or not, there are no variants.
Only compare based on total number - this way of calculation is by far the easiest, as it doesn't look at how the bonuses are made up, it just looks at the total as represented on the first page of your character sheet and what is in the Monster Manual. If your character has a +6 on Stealth, and the creature has a +5, the sheet will use +6 in the beast form.
I hope this adequately explains it
