1. "Your game statistics are replaced by the statistics of the beast, but you retain your alignment, personality, and Intelligence, Wisdom, and Charisma scores."
2, "When you transform, you assume the beast’s hit points and Hit Dice."
3. "You retain the benefit of any features from your class, race, or other source and can use them if the new form is physically capable of doing so."
The first 2 don't say anything about Proficiency Bonuses. So does 3 mean that a Druid uses their proficiency bonus instead of the beast's bonus while in Wild Shape?
You get the benefit of both. Wild Shape is the best!
As per the rules on Wild Shape (emphasis is mine):
Your game statistics are replaced by the statistics of the beast, but you retain your alignment, personality, and Intelligence, Wisdom, and Charisma scores. You also retain all of your skill and saving throw proficiencies, in addition to gaining those of the creature. If the creature has the same proficiency as you and the bonus in its stat block is higher than yours, use the creature’s bonus instead of yours. If the creature has any legendary or lair actions, you can’t use them.
You get the benefit of both. Wild Shape is the best!
As per the rules on Wild Shape (emphasis is mine):
Your game statistics are replaced by the statistics of the beast, but you retain your alignment, personality, and Intelligence, Wisdom, and Charisma scores. You also retain all of your skill and saving throw proficiencies, in addition to gaining those of the creature. If the creature has the same proficiency as you and the bonus in its stat block is higher than yours, use the creature’s bonus instead of yours. If the creature has any legendary or lair actions, you can’t use them.
Does that also apply to the bonus to hit an enemy?
The short answer is that it is complicated, far more complicated than Gruntler makes it seem. Build your druid in D&D Beyond, and look at the bonuses that you get, that is at least RAI if not RAW.
The part that is bolded above is really saying that for anything that you and the beast might both be proficient in (mostly skills, since we're talking about beasts), there are two ways you might calculate them: your druid proficiency bonus (monster proficiency bonuses are not printed in physical books) plus your stat bonus or the overall skill bonus already printed in the stat block of the creature. Choose the higher one of those. There are relatively rare cases where a druid might not be proficient in something but still have a higher bonus than a proficient beast in a physical stat.
But yes, you use your druid proficiency bonus whenever you need one. As I mentioned, monsters don't have printed proficiency bonuses. Some can be interpolated, and yet still some can be guessed at using the CR tables. D&Dbeyond also lists them in the stat block, but those are not printed in WotC materials. But RAI proficiency bonus is tied to character level, which I think would mean that you retain that part when you transform, even if it isn't perfectly described in RAW.
The Wild Shape rules are specific about what is retained from your character, and that does not include your proficiency bonus for attack rolls. So attacks use the beast form's proficiency bonus, which is determined by its challenge rating as shown in the basic rules and DMG online (I don't have a printed DMG to compare sorry).
If you're using D&D Beyond rather than books this is an easier solution because the beasts' attack actions already include their proficiency bonus, so you don't have to mess around calculating it yourself.
There are some parts that do require interpretation when it comes to wild shape. You only use your proficiency bonus whenever you are adding it to an ability score bonus, whenever you are using a total roll bonus that is already printed in the stat block, the creature's proficiency bonus is already included as needed.
I don't believe that RAW, there are any computations that don't involve one of those two methods.
Edit: that is to say there are no cases where you need to be able to figure out what the proficiency bonus of the creature is (according to my interpretation). Any place that you would need the creature's proficiency bonus, you have it already added to the other appropriate modiefiers. Any place that you need to add a PB to some other value, you would use the Druid's. For example, if you are concentrating on a summon beast or have some feature that you can use PB times per day, those would be based off of your character's PB.
The rules say:
1. "Your game statistics are replaced by the statistics of the beast, but you retain your alignment, personality, and Intelligence, Wisdom, and Charisma scores."
2, "When you transform, you assume the beast’s hit points and Hit Dice."
3. "You retain the benefit of any features from your class, race, or other source and can use them if the new form is physically capable of doing so."
The first 2 don't say anything about Proficiency Bonuses. So does 3 mean that a Druid uses their proficiency bonus instead of the beast's bonus while in Wild Shape?
You get the benefit of both. Wild Shape is the best!
As per the rules on Wild Shape (emphasis is mine):
The short answer is that it is complicated, far more complicated than Gruntler makes it seem. Build your druid in D&D Beyond, and look at the bonuses that you get, that is at least RAI if not RAW.
The part that is bolded above is really saying that for anything that you and the beast might both be proficient in (mostly skills, since we're talking about beasts), there are two ways you might calculate them: your druid proficiency bonus (monster proficiency bonuses are not printed in physical books) plus your stat bonus or the overall skill bonus already printed in the stat block of the creature. Choose the higher one of those. There are relatively rare cases where a druid might not be proficient in something but still have a higher bonus than a proficient beast in a physical stat.
But yes, you use your druid proficiency bonus whenever you need one. As I mentioned, monsters don't have printed proficiency bonuses. Some can be interpolated, and yet still some can be guessed at using the CR tables. D&Dbeyond also lists them in the stat block, but those are not printed in WotC materials. But RAI proficiency bonus is tied to character level, which I think would mean that you retain that part when you transform, even if it isn't perfectly described in RAW.
I think this might be a matter of interpretation.
The Wild Shape rules are specific about what is retained from your character, and that does not include your proficiency bonus for attack rolls. So attacks use the beast form's proficiency bonus, which is determined by its challenge rating as shown in the basic rules and DMG online (I don't have a printed DMG to compare sorry).
If you're using D&D Beyond rather than books this is an easier solution because the beasts' attack actions already include their proficiency bonus, so you don't have to mess around calculating it yourself.
There are some parts that do require interpretation when it comes to wild shape. You only use your proficiency bonus whenever you are adding it to an ability score bonus, whenever you are using a total roll bonus that is already printed in the stat block, the creature's proficiency bonus is already included as needed.
I don't believe that RAW, there are any computations that don't involve one of those two methods.
Edit: that is to say there are no cases where you need to be able to figure out what the proficiency bonus of the creature is (according to my interpretation). Any place that you would need the creature's proficiency bonus, you have it already added to the other appropriate modiefiers. Any place that you need to add a PB to some other value, you would use the Druid's. For example, if you are concentrating on a summon beast or have some feature that you can use PB times per day, those would be based off of your character's PB.