Every single Aesir is stronger than most humans. This grants them a +2 to their Strength. In addition, they gain a +2 to any other one attribute of their choice, and can claim close relation to one of the deific Aesir or Vanir as a result. For example, a character with a +2 to Dex might claim to be a nephew of Hermod, while one with +2 Charisma might claim to be Frey's grandson.

Upon reaching 8th level, the Aesir begins to understand the truth of Allspeech. At this point, the character can now choose to use it at any time, and be understood by all those who can understand a language of some kind that can hear them, and understand all those that are speaking within earshot. Since this is a literal translation, it does not allow the character to understand Thieve's Cant, which is usually code words, phrases, and strange slang. On the other hand, it does allow for the understanding of Druidic.

Anyone who hears the Allspeech hears it as if the user is speaking in their native tongue (and thus not, for example, Druidic). In addition, Allspeech has a magically telepathic componant, meaning it is impossible to either whisper or shout in Allspeech - if they can hear the speech at all, it sounds like normal volume conversation, and is intelligible to even those across a crowded room who pay attention. And finally, it gives no benefit for the written word, and only applies to actually speaking aloud or listening.

The Aesir is not required to speak in Allspeech. Instead, they may speak normally in whatever language(s) they know.

Due to their supernaturally long lives, Aesir are amazingly resistant to any effect that sparks aging. An adult Aesir becomes so at age 200, but have a potential lifespan of up to 3,000 years ( those that become deities, of course, live much longer).

When subjected to an aging effect, Aesir gain advantage on any saving throw. In addition, the amount of aging they suffer is reduced considerably - they gain the same amount of aging as a human would. A special ability or trap that would add 1 year of age for every decade of potential lifespan, for example, would only age an Aesir by 10 years, not 300. If the amount of aging is static, such as "the target ages three years", they age 1/10 the listed amount.

An Asgardian's vision is strange, as light is only one thing they can see.

At first level, an Aesir has normal vision, plus 30 foot Darkvision. This increases to 60 feet at 10th level.

At 6th level, an Aesir gains advantage to Perception checks for identifying the general area an invisible target is, due to their eyes being drawn to the environment's reaction to the passing of an invisible creature, such as dust around the feet moving, frass swaying the wrong way as it's stepped on, branches moving as the creature passes, etc. This does not apply if the creature has been flying or totally motionless for at least one full round prior to the perception attempt. This also does not allow the Aesir to see the invisible creature, only have a better chance of guessing the general area the creature is in - attack rolls, for example, would still be at disadvantage even if the general area is known.

In addition, an Aesir can cast Detect Magic once per Short Rest. This increases to twice at 15th level. It counts as a spell--like ability, as they are simply shifting the spectrum which their eyes can see, and thus this ability cannot be Counterspelled or Dispelled.

All Aesir hide the fact that every being of their race has some form of mystical vulnerability. In addition, the Aesir are a Fated race, doomed to perish when Ragnarock occurs (save Vidar, Magni, and Modi, plus Villi, Ve, Ask, and Embla shall be reborn).

When subjected to any form of prophetic spell, power, or ability, an Aesir will be unable to make any sort of saving throw, as it will become imposed directly upon them by the full deific power of the Norns. They may also only gain woeful results from, for example, the spell Augury; any other result would be silence.

In addition, each Aesir chooses a specific form of attack they are physically vulnerable to, preferably based on whoever their claimed divine relative is. A nephew of Balder, for example, might take double damage from wooden piercing attacks (such as arrows or wooden darts, but not spears or other piercing polearms unless made entirely of wood), while a grandson of Heimdall might be vulnerable to spells or attacks that target the senses, such as Hypnotic Pattern or Blindness/Deafness. They will take double damage if a damaging attack, and have disadvantage to any saving throw they must make against these attacks. If the attack is physical, and the character has Heavy Armor Mastery, as an example, this doubling of damage happens after Heavy Armor Mastery reduces the incoming damage.

Game Masters should be careful to work with the player on this weakness. It should make sense, and not be utterly obscure (only triggered when attacked by poison covered beehives, for example, is too ridiculously rare) or too crippling (double damage from all non-physical attacks).