Magic
When casting a level 2 spell players can use any spell slots of 2nd level or above to cast the spell. Although using a spell slot of a level higher than the spell itself will never give additional benefits
Um actually; Many spells have additional benefits when cast at a higher level
Bears are an interesting beast since they have 3 distinct forms. The brown, black and polar bears. Each with a different CR. The brown bear has a CR of 1/2, the black bear is CR 1, and the polar bear is the strongest at CR 2
Um actually; The brown and black bear's CRs are swapped
A bag of holding is a super handy common item. It remains the same weight no matter how much you put in so long as it doesn't go over the limit. Just don't put it in another extradimensional space, otherwise the item will implode and take everything in the area with it.
Um actually; The bag of holding is an uncommon magic item, not a common one.
Paladins are a very powerful class in D&D, with features such as Lay on hands, Divine Strike, and channel divinity. They are a force to be reckoned with in any setting.
Um actually; Paladins have the feature Divine smite, divine strike is a cleric subclass feature
The halfling race has a trait with the same name as a feat, Lucky, however these features work quite differently. A halfling's luck allows them to rerolls 1s, while the lucky feat can grant advantage or disadvantage on a roll, even after the first roll has been seen.
Um actually; Lucky doesn't grant advantage or disadvantage
The spell magic missle is great. There's no stopping the 3-11 darts of magical energy from dealing 1d4+1 force damage each.
Um actually; there are ways to stop the magic missle spell. (Shield, brooch of shielding, counterspell etc.)
The Rakshasa is a powerful demon immune to most magic. Only spells of 6th level or higher can even affect this demon with upside down hands. Although it does have a very big weakness. The Rakshasa is one of the few creatures with a damage vulnerability in 5E. This vulnerability being against piercing damage from a magic weapon, wielded by a good creature.
Um actually; The rakshasa is immune 6th level spells. So only spells of 7th level or higher can affect it.
There are many kinds of weapons in D&D but they're generally catagorized into 2 groups, simple and martial. Simple weapons are weapons that any class can use such as daggers, quarterstaffs, and shortbows. Meanwhile martial weapons can only be used by the more weapon focused classes like Fighters and Paladins. Although some classes like Rogue's have select Martial Weapon proficiencies like Rapiers.
Um actually; Some classes can't use every simple weapon
Wizards have more subclasses than anyone else, with each one representing a school of magic. And while each class showcases that school's unique focus some are clearly better than others. The most infamous example being the divination wizard with the ability Portent.
Um actually; Not every wizard subclass represents a school of magic
Half-orcs are one of the races that gains a skill proficiency for free. Their orcish ancestry gives them proficiency in athletics or intimidation. This compliments the idea that half-orcs are strong and scary, even with a lower charisma.
Um actually; Half-orcs can only choose the intimidation proficiency
The spell Finger of Death is a powerful 8th level spell. It deals a massive amount of necrotic damage both rolling dice and adding a flat amount. And if it kills the target they become a zombie under your control
Um actually; Finger of Death is a 7th level spell
Hags are an iconic creature in D&D with a wide variety of stat blocks. There's the CR 5 Night Hag, the CR 2 Sea hag, and even a CR 3 Green Hag in the monster manual alone. The hags have differing abilities but all of them are capable of casting a variety of spells.
Um actually; The sea hag does not have the spellcasting feature
Xanathar's guide introduced a lot of common magic items like the Mystery Key, Staff of Flowers, and Unbreakable arrow. But the common items in Xanarthar's weren't the first common magic item. Healing potions were the only official common magic item before Xanathar's guide, being a staple item with much discussion and house rules to improve them.
Um actually; The potion of climbing in the DMG is also a common magic item from before Xanathar's.
Xanathar's guide to everything is a great supplementary rulebook. One of the many things it includes is subclasses for the first 12 D&D classes. It has great options like Drunken Master for monk, war magic for wizards, and even Peace domain cleric.
Um actually; Peace domain cleric isn't a subclass in Xanathar's guide
The prodigy feat is only available to humans, due to their limitless potential and quick learning. This is due to their relatively short lives and explorative nature.
Um actually; Prodigy can also be learned by creatures that are half human like half-elves and half-orcs.
True Strike isn't a great spell for warriors, but for spell casters it can used to make that expensive spell attack just a little more likely to hit. Thankfully the spell lasts a minute so you've got plenty of time to set up your ambush on the bad guys, as long as you can maintain concentration on the spell.
Um actually; True strike only lasts 1 round
Naga's are giant intelligent snakes capable of casting spells. Because of their power Nagas eat so much food they can barely gather it themself. This leads to Naga's ruling over a domain with subjects to help it feed.
Um actually; Nagas don't require food, air, drink, or even sleep.
In D&D 5E a torch lights up a 40 foot area around the item. The first 20 feet of this area is bright light, while the remaining 20 feet is only dim light. This is important because dim light imposes disadvantage on perception and investigation checks.
Um actually; Dim light only imposes disadvantage on perception checks, not investigation
Monks can be a difficult class to play in combat since they're a melee class that would often rather attack with their bonus action instead of using a Ki point to run away like a Rogue. Even with their unarmed defense monks don't reach a high enough HP or AC to effectively tank for a party.
Um actually; Monks have unarmored defense, not unarmed defense
The Warforged is a great race receives a lot of amazing benefits. They get a +1 to ac, they're immune to disease, and even speak 2 languages besides common. They have many more features including an elf like immunity to magic that would put them to sleep.
Um actually; Warforged only speak 1 language besides common
The 9th level spell Wish can do almost anything. There's a few examples in the PHB like making gold, items or even replicating the effects of any spell up to 8th level. But if you use this spell there's a chance you can never cast it again
Um actually; When you use the spell to replicate the effects of another spell there's no chance of it never being cast again
As powerful as they are Vampire's actually have a lot of weaknesses. They're vulnerable to radiant damage, they take damage from running water and sunlight, and if they're staked in the heart the vampire is paralyzed until the stake is removed.
Um actually; Vampires are not vulnerable to radiant damage, it only stops their regeneration.
The Dwarven Thrower is a powerful magic item that only dwarves can attune to. It has both the thrown property and a +2 to hit and damage. If you throw this weapon at a creature it takes an extra 1d8 damage, 2d8 is the target is a giant. The best part is the hammer returns to hand immediately after the attack.
Um actually; The Dwarven thrower gives a +3 to hit and damage
In all of D&D 5E's time only 1 new class has been officially added since the original 12 of the edition. This class being the Artificer. However non-official classes like Matt Mercer's blood hunter and the Mystic can be found on official D&D websites like D&D beyond.
Um actually; The Mystic is not on D&D beyond
The minotaur, a race introduced in Ravnica, is a great class for a barbarian. With a +2 to constitution and a +1 to strength the minotaur is one of the best choices for an exotic front line tank. They're even great at getting into the fight their goring rush ability that allows them to make an attack with their bonus action, but only after using the dash action and traveling at least 20 feet.
Um actually; Minotaurs gain a +2 to strength and a +1 to constitution.