The icons for the achievements Hard Choices, The Order Is Revealed, The Good Saxon, Take My Hand, Calling in a Favor, The Enemy of My Enemy, and England Subdued display the numbers 1–7 using the pentimal system.
The achievement It's Alive! is a reference to the same line exclaimed by Dr. Victor Frankenstein in the 1931 film Frankenstein after successfully sparking life in his monster stitched together from scavenged human body parts.
The achievement We're in the End Game Now is a reference to the line said by the wizard Doctor Strange to billionaire industrialist Tony Stark in the 2018 Marvel movie Avengers: Infinity War shortly after losing a critical team fight against Thanos on his ruined homeworld.
The achievement Not the Norse You're Looking For and its icon are references to the famous line "These aren't the droids you're looking for" said by an old Obi-Wan Kenobi in the 1977 film Star Wars: Episode IV – A New Hope, as he waved his hand and used a Jedi mind trick to convince an Imperial stormtrooper to drop his scrutiny of the droids C-3PO and R2-D2 in Luke Skywalker's possession.
The icon for the achievement Seahorse depicts a medieval-style hippocampus.
The icon for the achievement Archaeologist shows a partial bust of the Aphrodite Heyl statue.
The achievements Godly Reward and Worthy are references to the Marvel character Thor, who wears a winged helmet in the comics of similar style to the one in the icon, while his hammer Mjölnir bears the runic inscription "Whosoever holds this hammer, if they be worthy, shall possess the power of Thor".
The icon for the achievement Know What is Right shows a sun with a signum manus, a Merovingian style of signing official documents with a royal seal. This symbol is used in-game as the signature of the Frankish king at the time of the siege, Charles the Fat.
The achievement Vive la Résistance and its accompanying icon are two different references. The phrase was a common saying of the French Resistance that fought the occupying forces of NaziGermany during World War II. The winged insect is not a bee but in fact a cicada, which as "golden bees" were seen as symbols of resurrection and were found on the tomb of King Childeric I, founder of the Merovingian dynasty that led to the formation of Medieval France.
The achievement Future Past may be a reference to the 1981 Marvel comic arc Days of Future Past, where the adult Kate Pryde sends her mind back in time to her younger body to warn the X-Men and prevent a dystopian future thanks to her hindsight. In a similar vein, astute players will already know the French Hidden Ones later evolve into the French Assassins due to the 2014 release of Assassin's Creed: Unity, which is set in the years surrounding the French Revolution and follows Arno Dorian's quests with the Brotherhood.
The achievement Vendage is French for "harvest", and the accompanying icon of a robed skeleton with a scythe is a common illustration in Europe and North America of the personification of Death, otherwise known as the Grim Reaper, who "harvests" souls for the afterlife.
The achievement Lèse-majesté is French for "to do wrong to majesty" and is used to describe offences committed against reigning monarchs or the state. Appropriately, the accompanying icon is a broken crown, as the rebel missions are meant to undermine King Charles' power.
The achievement Over the Hills... seems to be a reference to the 17th-century traditional British folksong of the same name.
The achievement See no evil is a reference to the the 17th-century Japanese adage to "see no evil, hear no evil, speak no evil". It often is represented by three Japanese macaques performing each action, and seems to have been inspired by a similar phrase from the 2nd to 4th-century Chinese text Analects, which holds a number of sayings attributed to the philosopher Confucius.
The icon for the achievement Crossing Dókkerland of a gloved, burning hand giving a thumbs-up as it sinks into flame is a visual reference to a scene in the 1991 film Terminator 2: Judgement Day, where the T-800 Terminator robot gives the gesture to Sarah Connor and her son John while willingly sacrificing itself in a vat of molten steel to prevent itself from being used as a template for future Terminators.
