This year has been moving fast, and your humble review gnome has really been having a hard time scheduling reviews for some of the really big projects out there. Turns out, while trying to keep up with life as well as multiple playtests for major projects, as well as major company faux pas that suck up all the oxygen in the room, it’s not always easy to do a review for an almost 500-page product.

Raiders of the Serpent Sea is a D&D 5e campaign utilizing themes from Norse mythology. This is a product from Arcanum Worlds, the same team that produced Odyssey of the Dragon Lords, a massive adventure product that explored Greek mythological themes through the lens of D&D 5e. The adventure itself is almost 500 pages long, but I still wanted to take a look at the project, so instead of tackling the entire adventure, I’m going to look at the Raiders of the Serpent Sea Player’s Guide.


I helped crowdfund this project, and my copies have come from my backer rewards. I have not had the opportunity to play or run any of the material in this product, but I am familiar with D&D 5e both as a player and as a DM.

Created by Brent Knowles
Writing and Design:
Brent Knowles
Additional Design:
Gage Ford, Atlantis Fraess, Carter Knowles, Linden Knowles, Brandon Korolik, Zack Webb
Marieke Feller Graphic Design and Layout: Michal E. Cross
Chris J. Anderson, Davis Clifford, Amy Cornelson, Michal E. Cross, Wadim Kashin, Sebastian Kowoll, Brendan Lancaster, Erikas Perl, Polar Engine, Tom Ventre World, City, and Dungeon Maps: John Stevenson
Additional Maps:
Chicago Fraess, Brent Knowles, Tiffany Munro Player’s Guide Cover
Polar Engine
Campaign Book Cover Art:
Sebastian Kowoll
Public Domain Paintings:
Wikimedia Commons
Stock Art:
Combat Maps:
Inkarnate (, Dungeon Alchemist (
Proofreading and Playtesting:
Chris Crowle, Lisa Crowle, Gage Ford, Atlantis Fraess, Chicago Fraess, Carter Knowles, Linden Knowles, Michael Rinsma

Format and Layout

The Raiders of the Serpent Sea Player’s Guide is 82 pages long, including a title page, a credits page, a table of contents, and a page for the OGL statement. Because the Player’s Guide is presenting information in the core adventure for potential players of the adventure, it shares the art assets of that book.

There are several full-page art pieces in this book, including a two-page spread of the setting map, as well as images of characters and creatures from the setting in addition to maps of various locations and ships. Each of the major clans of the setting also has its own faction symbol as well.


This book is broken up into the following sections:

  • Chapter 1: The World of Grimnir
  • Chapter 2: Creating Heroes
  • Chapter 3: Playable Races
  • Chapter 4: Class Archetypes
  • Chapter 5: Ships of the Sea
  • Chapter 6: Grimnir World Primer

There is some overlap between Chapter 1 and 6 in terms of the information presented. Chapter 5 isn’t a definitive listing of everything related to ships that the setting has to offer, but does present ships that are either common to the setting or important to the story of the setting, in a format that matches the vehicle rules presented in the Dungeon Master’s Guide.

The Setting

Grimnir is a relatively young world that was born out of the death of an older world. The primary deities of the setting are heroes that ascended to their godhood due to the events that destroyed the old world. Aldyhn, a goddess with traits of both Odin and Frigga from traditional Norse folklore, killed Mirgal, i.e. Loki with a little bit of Odin as well, and formed the new world from his corpse.

This new world is filled with primal extremes, like volcanos, great expanses of sea, and towering mountains. Aldyhn called creatures from across the worlds to populate this new land, and many creatures include giant and dire beasts, as well as ice age species of animals.

The gods were turned to stone through trickery, but still exert their will through their followers. The Yoten, powerful spellcasting giants, are thought to be dead and gone. Thonir, the “almost god,” son of Aldyhn, sits in Valhalla waiting for another Ragnarok to happen. Hel (the only Norse deity that gets to keep her name in the setting) collects the non-valorous dead.

The mortals in this young world are divided into the Raider clans, and the Baendur Kingdoms. The Baendur Kingdoms exist, from a story standpoint, to be raided. The heroes of this story aren’t assumed to come from that land. That doesn’t mean that the PCs will only be Raiders, however. Like Odyssey of the Dragon Lords, Grimnir is assumed to have various visitors from other worlds that arrive due to the shattered Rainbow Spear, meaning you can create a character native to another D&D setting and use this in this adventure.

The Raider clans are further divided into factions, each residing in different locations, with different specialties, and with traditional player species associated with them. For example, the Lutan are traditionally composed of human and dragonborn families, while the Knattle are primarily human and dwarf families. While the clans are often in conflict, at certain times they come together for a great meeting and form the Drifthall, a collection of ships bound together to create a massive seaborn settlement for the duration of the gathering.

In addition to the idea that Mirgal’s essence is still infused into the setting, and the Yoten may not be as dead as they seem, the Witch King is a looming threat that leads the witches of the Ironwood. For the last few years, winter has never fully left the land, and the PCs are assumed to be joining a great expedition that has been founded to journey to the southern edge of the world.

Gear and Equipment

The gear introduced in this guide isn’t too extensive, in part because anything magical or legendary is reserved for the GM in the primary adventure. The standard Viking sax (short sword/dagger) and skeggox (handaxe and woodworking tool) are included, as is the gambeson, a light suit of armor that can be worn to enhance other armors at the cost of stealth and movement speed.

Ironwood weapons are considered magical, but don’t require any particular ritual or magical components to create. That said, it is noted that it’s really difficult to work with ironwood to make it into a weapon in the first place.

Ships get their own section, if only to introduce players to the kinds of ships they are most likely to know about. The guide details three different styles of longship, the carver, the charger, and the explorer, as well as the Faering and the Mercanskip of the Baendur Kingdoms. My favorite addition is the Hjemskip, a floating gathering hall that is used by the clans when attending the Drifthall. These are slow and bulky, but I love the idea of a mobile home base in this kind of setting.


The Player’s Guide introduces mechanical elements that include rules for Oaths, Glory, Epic Backgrounds, new player species, new subclasses for all twelve of the 2014 Player’s Handbook classes, and new spells.

There are three different Oaths detailed in the Player’s Guide, which can result in specific curses if those Oaths aren’t upheld. The Oath of Duty is basically a way to make sure both sides of an agreement get upheld. The Oath of Fellowship binds characters together, and lets them share their Glory. The Oath of Retribution gives bonuses to defeat a specific foe, but must be executed within a set amount of time.

The Curse of the Exile makes it impossible for other Raiders to aid the afflicted character. The Curse of Failed Promises progressively afflicts the character with levels of exhaustion until they die and rise as a draugr.

There is a table tracking the benefits and effects of Glory, from 1 to 20. The benefits of gaining Glory can be advantage on certain checks in specific circumstances, tribute paid to you when visiting lands affected by your deeds, or NPCs dedicated to your service. At certain levels, you may have to react to challenges to your reputation, meaning that Glory isn’t just a benefit, but can also serve as a story trigger as well.

I like the idea that you can wager your Glory to make a boast, introducing a risk/reward aspect ot this mechanic, and I also like that the different tiers of Glory on the list include various points where people will challenge the PCs as their fame and reputation gets higher, and that it doesn’t just serve as only a list of additional benefits the PCs receive.

Epic Backgrounds

Arcanum Worlds has used mechanics similar to Epic Backgrounds in both their DMs Guild adventures, Heroes of Baldur’s Gate, as well as Odyssey of the Dragon Lords. An Epic Background still provides proficiencies, languages, and equipment. They may have more than one Feature, one of which involves a Rune associated with your path in the story, and a more traditional Feature, like gaining advantage when using skills in a specific instance.

Epic Backgrounds also include a starting story connection, which ties you into the beginning of the adventure. There are also heroic tasks, which grant you a reward when you complete that task, and an Epic Goal, the culmination of what you have been attempting to accomplish, which grants you a major reward as well.

The Epic Backgrounds included in the Player’s Guide include:

  • The Bonded (someone whose fate is tied to one other specific person)
  • The Cursed Raider (someone who can’t die, and can’t get into Valhalla)
  • The Fallen (someone that can’t remember their past beyond the last few years)
  • The Royal Heir (a royal from one of the Baendur Kingdoms living with the Raiders)
  • The Stranger (someone that wandered into Grimnir from another world)
  • The Vigilant One (someone from a family concerned that the Yoten would return)

In previous adventures that used this mechanic, the heroic tasks and epic goals from these backgrounds aren’t random events that the DM should add or that the players need to orchestrate, but are often events that happen in the narrative of the adventure, or additional side quests that unfold if anyone has the appropriate background when they encounter an event in the adventure.

I really appreciate having backgrounds that create natural ties into the adventure. One of the biggest bits of advice given out to DMs running published adventures is to personalize it for your players, and having backgrounds that they can pick that tie them into various events goes a long way toward helping the DM do this. That said, it’s not a perfect solution.

For every one of the Arcanum Worlds projects that have used this convention, I’ve always wished for just a few more backgrounds. To use the above as an example, if you have a group of six players, and everyone wants to be from the Raider clans, two of the backgrounds explicitly lean away from that theme. Additionally, if a player changes character, or someone new enters the group, those new characters may have much more constrained options available to them, unless you double up on backgrounds, and make them a little less special and unique in the party.

Additionally, when I tried to run Odyssey of the Dragon Lords, I ran into an issue I was not expecting. Even though my players were playing in a published setting, and the backgrounds tied them to the adventure, several of them actually didn’t like the idea that there was an existing “right” answer for their various tasks. In that particular adventure, for example, the player with the Demigod Epic Destiny didn’t like that the background assumes you are the child of one specific god, and that the story connections are all based on that assumption.

Playable Races

A lot of more recent 3rd party publishers have moved towards using another term for race, even if “species” isn’t the 100% certain replacement term in D&D for the 2024 rules. Unfortunately, this product doesn’t move away from the term, but it does design these player options with the assumption that you can assign your ability scores as you want, in a manner similar to current D&D norms (+1 to one, and +2 to another, or +1 to three).

The species included in this section are all meant to be native to the setting, and they include the following:

  • Beastborn
  • Grim
  • Tallfolk
  • Tuss
  • Wicker

I love the folkloric feel of the Beastborn, as they are literally animals that watched humans for so long they just decided to act like them. There aren’t communities of Beastborn, there is only the phenomenon that sometimes an animal pays so much attention to humans that it stands up on its hind legs and starts to do things like a human. Beastborn can communicate with creatures of their original kind, but the rest of their traits are custom-built with a point buy system.

Grims are aquatic humanoids that are intrinsically tied to the world of Grimnir, including the essence of Mirgal that was used to create the world. That means that Grim can switch between two drives every long rest, Hopeful and Cruel. A Hopeful Grim has advantage on performance, can grant proficiency with musical instruments, and at higher levels can cast sleep or suggestion, and can use their own spell slots to cast those spells beyond the one time per long rest they can use them based on their nature. A Cruel Grim has advantage on stealth checks, does extra damage based on proficiency bonus, and can cast fog cloud and invisibility at higher levels.

Tallfolk are essentially half-giants, although their background is shrouded in mystery, even to themselves. Tallfolk are a Large player option, do extra damage and can throw weapons farther than normal, and they have reach. They can use a reaction to retaliate against a foe, but it moves them down the initiative track, and they can only use it once per short rest. There are two subcategories of Tallfolk, Earth Children or Cold Children. An Earth-Child has advantage to Stealth in certain environments, while a Cold-Child has resistance to cold.

The Tuss are born to humans, but bear the essence of the Yoten within them. This isn’t evident unless they use their True Nature trait in front of others, which causes them to take on a more monstrous aspect. Without accessing their True Nature, Tuss can spend hit dice when they drop to 0 hit points, once per short or long rest. If they show their True Nature, they have darkvision, add half their proficiency bonus to damage, move faster, and are less persuasive and more intimidating.

Wicker are wooden constructs that come in two different types, Builders and Watchers. All Wicker move more slowly than other species, have a natural armor bonus, don’t need to worry about eating, drinking, or catching a disease, and are resistant to poison. They are also vulnerable to fire. Builders have extra limbs that can have built-in features like extra movement, tools, a permanent shield arm, or a permanent weapon arm, and can switch between them on a long rest. Watchers are constructed to look like a living being, and gain advantage on Persuasion and Insight checks. They can also rip off their face to permanently become Builders.

There are a lot of story-heavy folklore elements to these species, which is great for the adventure. That said, not all of these hit the mark for me. Some of them are just a little too ambitious and push out into aspects of 5e that don’t have enough support to hold the rules elements introduced.

I love the Beastborn’s story, but I’m not a fan of point-buy systems for species. There are two main reasons for this. One is that just seeing that list of options is going to turn some players off that would otherwise love to play this species. The other is that some options are meant to be hindrances that add points back to the pool, and the fiddly math involved in that kind of species building can lead to unforeseen combinations.

While I have seen people cite spellcasting as one reason D&D 5e hasn’t ventured into Large sized characters (for example, pushing out the range of effects that originate from your character), D&D 5e just doesn’t have the same scaling structure that 3rd edition had. The Monster Manual seems to follow the pattern that Large weapons do double damage compared to regular weapons, and that Huge weapons do triple damage, but the only thing that really supports using a Large weapon is a footnote at the bottom of the monster building section in the Dungeon Master’s Guide. Spells like Enlarge don’t rescale your weapons to being Large, they just add a bonus die of damage. Given that the Tallfolk have bonus damage and additional range to thrown weapons, I think the assumption is that Tallfolk are just using regular weapons, but even then, there aren’t a lot of rules surrounding how a Large creature using Medium weapons functions. Can they use a Two-Handed sword with one hand? It’s not defined in D&D 5e. But beyond all of the size concerns, I really don’t think it’s wise to introduce a rules element that changes initiative after combat starts.


The subclasses presented often have an association with one of the clans of Raiders. The guide mentions that you don’t need to enforce this as a hard and fast rule, and some of the subclasses feel more tied to the story of their clan than others.

The Barbarian Path of the Provoked is, at least in part, about getting revenge, and gaining a spendable currency when they get hit to do extra damage. At higher levels, they can Dash as a bonus action, giving opponents vulnerability to their damage when they hit they, and choosing between effects like getting an extra attack when attacking recklessly or stunning an opponent with a hit.

The College of Seers Bard can bestow Bardic Inspiration dice on enemies, afflicting them with a specific curse. They get an extra attack at 6th level, as well as gaining the ability to give bardic inspiration to allies that have a persistent effect. At 14th level, they get additional effects added on to their curses when afflicting enemies.

The Cleric Discovery Domain makes the cleric really good at Survival or Perception, as well as granting them a swim speed. Their Channel Divinity option lets them determine how far away a location is and what direction it lies. They can also Channel Divinity to create a Wrathful Flood that does damage and pushes back opponents. They get a version of Divine Strike at 8th level, and at 17th level they do more damage with their flood, become better swimmers, and can breathe underwater.

The Circle of the Devourer Druid taps into primal energy to modify the druid’s form. As a reaction they can manifest a defensive mutation a proficiency bonus number of times per long rest. They can use Wild Shape to take a primal form, giving them natural bludgeoning, slashing, or piercing attacks, as well as a second attack with their natural weapons. At 10th level they gain special senses in their primal form, and at 14th level, primal protection is restored on a short or long rest, and they can pick the result instead of rolling for an effect.

The Marauder Fighter can push opponents more effectively, as well as move away from opponents that have damaged they. At 7th level they can do a ground strike that can push and knock prone creatures near them. At 10th level, if an ally near them drops an opponent, they can use a bonus action to move and make another attack. At 18th level, they can command opponents to move on a threat, using their reaction to move and attack.

The Monk Way of the Wanderer is an interesting subclass, in that there isn’t an order of Wanderers, there is one Wanderer that learned to be a Wanderer from the last Wanderer. The story of this class is that they wander the land trying to rebalance everything. When they take certain actions, they add or subtract points from their Path of Fate score, which tells them what abilities they have active, and if they are Order or Chaos themed.

The Paladin Oath of the Slain is all about Paladins that are going to get into Valhalla and show others how to get there, too. Their Channel Divinity options include healing others when they hit an opponent, or to mark an opponent so they can get a critical hit on them with an 18 or better. Their aura grants a bonus die that can be rolled and added to hit against enemies. Glorious Sacrifice at 15th level means they can’t become undead, and they can keep going at 0 hit points, but keep taking failed death saves if they get hit, for the next round. Their “avatar” ability gives them resistance to all damage, immunity to being charmed, and the ability to use a reaction to hit an enemy their allies have just hit with advantage.

The Wolf Rider Ranger gains a special wolf at 3rd level, which can be commanded to take actions as a bonus action. They also have enhanced effects when they take the Dodge or Help action. At 5th level, their wolf grows up and they can ride it, and they gain special effects when mounted. Pack Leader gives them special benefits when near their wolf, like being able to hide them from line of sight or letting them shoot at point blank range. Eventually their wolf grows up even more, and increases their crit range when they help them attack. At 15th level, when their wolf gets a critical hit, they can move and attack as a reaction against another enemy.

The True Believer Rogue got into a bad spot at some point, desperately prayed to Mirgal, and now gets divine spells. They get the same spell progression as other spellcasting subclasses of non-spellcasting classes. At 9th level they can basically gamble and give an ally double what they would give them in healing as temporary hit points. At 13th level, they gain a proficiency bonus number of extra times that they can add extra radiant or necrotic damage to their sneak attack, which refreshes on a long rest. At 17th level, they can attempt a check to ask for all of their expended abilities back, but if they fail, they gain a level of exhaustion.

The Misplaced Soul Sorcerer is someone that may have been an extremely real illusion created by Mirgal that has gained sapience. They can summon Misplaced Souls (from a stat block in the subclass) to aid them, and they gain additional effects that interact with this feature on which they can spend their sorcery points. Eventually, they can merge multiple misplaced souls to gain multiple special effects, but the combined misplaced souls may randomly become real people.

The Warlock Patron of The Ironwood is a patron that is the essence of an especially old Ironwood tree, a remnant of the Old World that died as Grimnir was born. Many of the Warlock’s abilities surround the heartseed, which can grant temporary hit points and enhance speed at lower levels, then at 6th level can turn into armor with specific effects. At 10th level, they can merge with trees. Intelligent trees heal them, while unintelligent trees just blow up. At 14th level, they can ride around in giant tree armor that gives them extra hit points, a slam attack, and other abilities.

The Cohesion of the Primal Wizard is a tradition of Wizards that seeks out ancient, primal sources of power. The tradition is split between Dreamers (those seeking to find lost or new power sources) and Seekers (those seeking to suppress ancient and dangerous new power sources). Dreamers can swap spells known from their spellbook, while Seekers are excellent investigators that can expend spell slots to detect other spellcasters. Dreamers can cast spells and not have them take effect until a given time, while Seekers can remove spells from an opponent’s mind by making them forget the spell in the past. At 14th level, Dreamers can cast a spell when they fail a concentration check, and Seekers can curse an opponent to deny them the use of a specific spell.

In general, I like most of these subclasses, but there are some speed bumps on my road to enjoyment. I’m not sure if the Path of the Provoked means that you sacrifice an attack action or an attack to turn an attack into an area attack, because that’s an important distinction, and I feel like maybe it was meant to be an attack action, not a single attack. The Marauder’s story is that they are a raid leader, but until 10th level, they are actually just a fighter good at fighting on boats. The Oath of the Slain’s Mark of the Executioner feels a little weak compared to features that grant vulnerability to damage, for example. It might pay off long term, but it’s less satisfying than getting a big swell of damage on a single hit. The wolf stat blocks for the wolf rider use proficiency bonus for damage, but not anything else, but if everything scaled with proficiency bonus, they could have slimmed down the number of stat blocks.

I think the Wanderer Monk could be fun, but because of the constant tracking of the character’s point total to see what abilities they have available, it may be a tricky subclass to get a good feel for. I think the Misplaced Soul may also share this balance between a fun theme and the effort put into using the abilities.

The College of Seers, Circle of the Devourer, Wolf Rider, True Believer, and Ironwood Patron are my favorite subclasses of the bunch, both for doing fun things with the mechanics and for reinforcing their stories well.

New Spells
 There are a lot of fun elements in this Player’s Guide, even though there are a few places where it feels like the ambition of the final effect got a little ahead of the mechanics. 

I’m not going to go into a deep dive on all of the new spells, but I did want to touch on how on theme some of these spells are. Fair Play gives a smaller animal a boost when fighting a larger one. Rings of the Wise creates arm bands that can add to a caster’s defense, or be thrown and caused to blow up. Blood Sharing involves contributing blood to a circle of allies to share the effects of healing spells. They all pick up on some theme from Norse stories and make them just a little more fantastic to fit in with D&D.

Final Thoughts

There are a lot of fun elements in this Player’s Guide, even though there are a few places where it feels like the ambition of the final effect got a little ahead of the mechanics. I think the guide does a good job of introducing players to the setting with enough information to know what they are getting into, without deluging them with content.

Looking at this product on its own, as a way to introduce Norse-themed game rules into your game even if you don’t use the adventure, I think you can use it that way, although some of the species definitely feel tied to a greater story that isn’t even fully explained in these rules. For example, I’m not sure how the Tall Folk story is going to compare to the Tuss, since the Yoten are a type of giant. I do think some of the species options get a bit messier than the subclass options, and if you’re not going to use the Raiders on the Serpent Sea adventure, the expanded rules for Goliaths that we saw in recent Unearthed Arcana playtest rules look to address half-giant characters well.

The glimpses at the greater setting, and the implied story of the campaign, do make me want to carve off some time to dive into Raiders on the Serpent Sea in more depth. I enjoyed Odyssey of the Dragon Lords, and think it did a good job engaging with classical Greek mythology, which is a good recommendation for how Raiders might present a Norse epic.