Urdnot Wrex (Mass Effect)

Urdnot Wrex


Mass Effect was a landmark video game trilogy released from 2007 to 2012. It included multiple ties-in such as novels, comics and an animated movie. Further games will follow in 2016 and beyond, although they will form a separate storyline.

It is a science fiction story, of the starships and space aliens kind. Most of the action takes place in a military context, as an apocalyptic threat against the galaxy emerges. It’s one of my favouritest games ever.

Writeups.org offers extensive Mass Effect coverage. The core articles are setting for Mass Effect 1 and the setting for Mass Effect 2, plus the profiles for the heroine – Staff Commander Mandala Shepard.

Unless you are highly familiar with Mass Effect, we recommend reading these articles first.


  • This profile includes a few sentences based on the comic Mass Effect: Foundation #2, which details the events that take place just before Wrex appears in the first Mass Effect game.
  • This profile assumes a specific video game playthrough – see our video games writeups FAQ for more.
  • This profile features tabletop RPG mechanics about the video game’s gameplay – see our video games writeups FAQ for more.
  • This profile features non-canon hypotheses about in-game events and mechanics – see our video games writeups FAQ for more.


  • Real Name: Urdnot Wrex (meaning “the person called Wrex, of Krogan clan Urdnot”).
  • Marital Status: Single.
  • Known Relatives: Warlord Jarrod (father, deceased).
  • Group Affiliation: Crew member on the SSV Normandy.
  • Base Of Operations: Mobile aboard the SSV Normandy SR-1.
  • Height: 7’4” Weight: About a ton.
  • Eyes: Red Hair: Unrevealed, presumably N.A..


Powers and Abilities

Wrex is a Krogan. A huge, very strong, very resilient toad-dinosaur humanoid with a talent for violence and a fearless nature.

Krogans are optimised hunter-killers, driven by harsh evolution. They :

  • Have impossible endurance.
  • Have redundant organs.
  • Can store nutrients and liquids in their dorsal hump for lean times.
  • Have enhanced aggression.
  • Can withstand very harsh environments.
  • Can ignore nearly all toxins.
  • Can quickly regrow tissues.
  • Can endure impossible levels of radiation exposure.
  • Etc..

A Krogan finds it easy to kill most things, and most things find it very hard to kill a Krogan.

Wrex is a highly experienced mercenary, bounty hunter and thug for hire. The Krogans’ hardiness extends to their lifespan, and Wrex has been off-world for about 300 years now – which is a lot of combat experience. Wrex is confident that he’s good enough to overcome daunting odds, and so far he’s always been right.

Battlemaster, part 1

Wrex further builds upon these advantages as he’s one of a now uncommon breed – a Krogan Battlemaster. Battlemasters are trained in traditional martial arts (hand-to-hand combat and melee weapons), modern military skills (chiefly firearms) and biotics.

The most distinctive biotic skill of a battlemaster is wrapping himself in a Mass Effect kinetic barrier.

Urdnot Wrex points his shotgun

It takes an enormous volume of fire to take down a Krogan Battlemaste, between :

  • The barrier.
  • Their natural resilience.
  • Any armour they might wear.
  • The shields this armour might sport.

This endurance makes it feasible for them to charge their opponent and fight in melee – compounding their advantage.

Battlemaster, part 2

Wrex thus usually fight up close with a shotgun reinforced to be usable as a club. However, Shepard had him switch to normal assault rifle-based tactics so he could operate as part of her unit. As one of her men, the experienced Wrex fights much more like a Systems Alliance commando than a charge-happy young Krogan.

Battlemasters also know typical biotic powers of telekinesis, generally used to :

  • Throw people around to stun them.
  • Create molecular disruption fields.
  • Immobilise people in mid-air.
  • Etc..

They often use these abilities to keep dangerous opponents out of the fight while they kill their allies – so they then can have a real fight with the main foe.


Krogans evolved on the harsh, deadly world of Tuchanka. They hacked their way to the top of the food chain through sheer hardiness, strength and orneriness. Their technology developed over time, but their culture stayed relatively static.

Unsurprisingly, it didn’t take long after the Krogans discovered atomic physics for them to literally bomb themselves back to the stone age.

Urdnot Wrex facing Commander Shepard

The Krogans were hardy enough to endure the nuclear winter and radiation, albeit in much diminished numbers. They survived by the skin of their teeth, reverting to hunter-killer societies. Apparently, all their pre-apocalypse knowledge was lost.

Krogan tribes experienced a high death rate from their barren, savage, toxic environment. Yet their high fertility rate allowed them to replace their losses.

First contact

Tuchanka was later discovered by Salarian explorers. The Salarians were impressed by the toughness and aggression of Krogans, and sought to use it to their advantage. At that point, the Council races (dominated by the Asari and Salarians) had been losing a lengthy bloodbath against the Rachni – aggressive space bugs.

Seeing a chance to save Council civilisations, the Salarians offered the Krogans culture and technology in return for military service. Eager to fight new opponents with bigger weapons, many Krogan tribes took the deal.

Urdnot Wrex character model sheet, high angle shot

The plan worked brilliantly. Krogan warriors were a match for the Rachni, and once free from the deadly and drained environment of their home planet, their incredible fertility took over.

Krogan shock troopers were the vanguard of Council forces. They were even capable of fighting on poisonous Rachni worlds. They hunted down every last Rachni to the bitter end after decades of intensive fighting. Council civilisations were saved.


However, the aggressive Krogan continued to breed, and they now lived in environments unable to kill them. Within a few generations the demographic pressure was untenable, even though Krogans had been granted the Rachni worlds as colonies.

The Krogans retained their brash and aggressive nature. Thus after a series of incidents with other Council species war erupted – the Krogan Rebellions.

The Rebellions were much like the Rachni Wars, lasting for centuries and exhausting the Council forces as the fought powerful enemies who could breed quickly to replace their losses. The situation was essentially back to what it was centuries before. The solution had become as bad as the problem.

The genophage

Once again it was a newly-discovered species that saved the Council. The Salarians and Asari approached the Turians for help, and these militaristic newcomers to Citadel Space went on the warpath.

Urdnot Wrex scowling

The Turians discovered that the Salarians had developed a biological weapon called the Genophage. It could cripple the Krogan’s astounding fertility. Salarians did not wish to use this weapon for ethical reasons, but the Turians did not care and deployed the Genophage.

Unable to replace their losses, the Krogans were beaten back to the former Rachni worlds by the Turians – who were much better organised and far more disciplined.

Spectre of extinction

The Genophage resulted in spontaneous termination for roughly 99.9% of Krogan pregnancies. This was a time of chaos, and the tribes soon fought among themselves and/or broke down into civil war.

Given their intrinsic aggression and the sense of despair, only a handful of Krogans could muster the wherewithal to do something more constructive than fighting to the death at any provocation.

Urdnot Wrex character model sheet

That was actually the cause of the problem. The Genophage had been engineered so the Krogans could maintain, but not expand, their population. However, insisting on fighting and dying meant that Krogan population would steadily dwindle.

Urdnot Wrex was one of the few who realised this. Though he loved violence as much as the next Krogan, he saw the necessity of fixing the imminent extinction problem, and campaigned for an extended truce and unity among tribes – if only to focus on reproduction for one generation.

Warlord’s son

Wrex’s main opponent was his own father, the old-fashioned Warlord Jarrod. Jarrod was one of the few warlords who had survived the war, and apparently commanded vast power among the Krogan survivors.

(Since Wrex stated that he led a small tribe, it is likely that his tribe was affiliated to a nation of tribes, or another form of inter-tribal alliance, led by Jarrod.)

Urdnot Wrex face closeup

Jarrod apparently considered that his son and his followers were betraying everything that made Krogans Krogan. He summoned his son to talk in peace on sacred ground. Jarrod did not hesitate to violate the ancestral sanctuary, killing Wrex’s partisans – but was killed by his son in return.

Wrex had to flee Krogan space, and established himself as yet another roaming Krogan merc.

When you are older, the best fights come to you

Wrex lived in exile for three centuries, killing for money and serving whoever promised the most action and pay. His activities ranged from law-abiding bounty hunting to outright piracy and slaughter.

He generally worked alone. His experiences with joining private armies and warbands weren’t to his liking, though he was okay with joining small units for one operation, such as a pillaging raid.

As a redoubtable Battlemaster, Wrex developed a strong reputation. He apparently became a top-shelf, very experienced and efficient mercenary. When he was encountered he worked for what seemed to be the most important intelligence-bartering network in the galaxy, the Shadow Broker.

Wrex was apparently one of his top hitmen. In 2183 he was hired to terminate a crime lord on Citadel who had foolishly betrayed the Broker.

The Fist job

As Wrex boarded the Citadel to verify whether the target — a Human named Fist — had indeed betrayed the Broker, he ran into a number of obstacles These ranged from customs having been alerted that his shuttle was carrying contraband, to gangs of street toughs thinking that he had wronged them – to a full ambush by professional mercenaries.

Though Wrex never determined what was going on, these delays had been set up by a crack Cerberus agent looking to contact Fist. This Human expediter who would later go by “Maya Brooks”.

Urdnot Wrex and Commander Shepard

Though Wrex did reach Fist, “Brooks” tricked C-Sec into intervening. She also warned Fist that the Krogan had him marked for death.

Albeit he refused the Cerberus offer, Fist played along and told C-Sec that Wrex had been threatening him. The cops briefly questioned the Krogan, but they didn’t have genuine charges to stick on him.

Enter the dragon

However, a team of Human marines led by famous war heroine Staff Commander Shepard then approached Wrex. The soldiers had been looking for information on the Citadel. From Shadow Broker agents they learned that they needed to talk with Fist. The Humans contacted Wrex as a likely ally to “approach” the crime lord.

A firm believer in enemies of enemies being friends (at least for the duration of a firefight), Wrex agreed to join forces. He soon discovered that he had found the rare group with which he wouldn’t mind forging a long-term association. Furthermore, these people were diving right into a very tense situation that would involve lots of fighting and poor odds.

Wrex offered to join Shepard’s crew on a retainer basis, and she took the offer. From context one gets the impression that Wrex asked for but a symbolic retainer, and mostly joined for the action.

Between his experience, his strength and his extraordinary resiliency, Wrex became a pillar of Shepard’s tactical team – to his satisfaction.


Wrex and Shepard eventually discovered that Saren, the madman they were chasing, had set up a lab on a planet called Virmire. This fortress held extensive medical and breeding facilities from whence a Krogan army would spring.

Apparently, Saren and his scientists had discovered a mean to cure or at least bypass the Genophage, probably through cloning.

Wrex was extremely conflicted. He had to choose between his loyalty toward Shepard (who wanted to destroy the lab to prevent an unstoppable army from serving Saren) and the future of his species.

After a tense discussion, the powerfully charismatic Shepard convinced Wrex that the future of the Krogans was not to be slaves to Saren. Subsequent revelations about Saren’s plans would prove her right.

Wrex served faithfully and insisted on personally putting the last bullet into Saren’s head when the time came.

Mass Effect 2 — back from exile

Still ruminating over the Virmire incident, Wrex saw how Saren’s plan could give him the material he needed to rally Clan Urdnot to him. His discussions with Shepard had given him the inspiration to wrap up centuries of ponderings about the future of the Krogans.

Returning to Tuchanka, he took control of Clan Urdnot in unchronicled circumstances. His new policies made Clan Urdnot — already renowned for its tactical acumen — the dominant clan on Tuchanka within two years.

Urdnot Wrex on his ME2 throne

(What were Wrex’s takeaways from Virmire is unknown, but one imagine that revolved around the Krogans being unable to develop a cure for the Genophage by themselves. Thus, hoping for a cure was putting themselves at the utter mercy of whoever would develop one. Krogans’ only hope for continued independence was to learn to make do with the Genophage rather than wait for the next Saren and learn what his price would be.)

A change is gonna come, part 1

Wrex’s groundbreaking policies were an unprecedented mix of alien ideas and Krogan traditions. They valued economic development and population growth just as much as war and glory.

What little scientific resources Urdnot had were turned toward agriculture and medicine rather than “Krogan science”, which was previously a synonym for demolitions and weapons engineering.

There were many malcontents about this even within Urdnot. But Wrex was strong and those whom he convinced were loyal and ready. The shaman of Clan Urdnot also clearly threw his lot behind Wrex – which, given his role as the incarnation of Krogan spirit and traditions, was an important support.

The most unusual development was hammered out with the leader of the female half of Clan Urdnot – Clan Leader Uta. A neutral ground was created where fertile females of all clans were welcome to join the Urdnot women, and the economy and security of the women’s territory was backed by Wrex’s men.

A change is gonna come, part 2

The initiative was successful. Many women came to the new “country”, indirectly joining Clan Urdnot and making it impossible for other clans to attack Urdnot directly.

Urdnot Wrex using his biotics, by Proboi91

Working with Uta to set up breeding alliances between the new women’s meta-clan and the traditional clans was a keystone of Wrex’s policy to ease up on the war and dying – and stop depopulation.

(While it’s never explained in the game proper, one assumes that the miscarriage rate varies by individual, and that some Krogan women have something closer to a 99% rate (or less !) rather than the normal 99.9%. These are presumably those whom Wrex call “fertiles females”, in that dozens or even a hundred attempts at getting pregnant is much more feasible than a thousand. Conversely, some Krogan women are left essentially barren by the Genophage, being on the other end of the miscarriage rate distribution.)

Enough Krogans could see the value of sharing fertile females to back Wrex’s law-enforcement policies around the women’s clan. Basically “behave around the fertile females or be expelled and destroyed by them, Urdnot males, and their allies”.

Rise of the women’s clan

Several clans were demolished by Wrex and his allies for attempting to raid the female clan. This convinced the rest to toe the line – and convinced more fertile females to join the battle-proven secure enclave.

Wrex also forbade Urdnot warriors from killing noncombatant women and children during raids. In good part this was to show how serious he was about stopping the Krogan population’s collapse.

Clan Leader Wrex and Clan Leader Uta used their leverage to push Krogan cultures toward becoming permanent allies, coordinating their efforts and sharing their best qualities until war would become pointless.

This sort of European Union of Krogans was expected to take centuries and much bloodshed. But Wrex wanted his species to see the light, even if Urdnot was to lose dominance at some point to allow for that.

As a pilot project, Wrex and Uta started forging a permanent alliance with a small clan, Nakmor. While minor it was respected for the deeds of its warlord Nakmor Krall during the Krogan Rebellions.

Can’t keep a good girl down

In 2185, Wrex was happily reunited with Shepard. She came to visit – and to conduct a combat rescue operation to fetch a Salarian stranded elsewhere on Tuchanka. Wrex made it clear that Shepard was one of the very few aliens with clearance to operate on Urdnot turf.

After Urdnot rivals Clan Weyrloc had the terrible idea to try to kill Shepard, Wrex ostensibly offered the survivors to join Urdnot. Many Weyrloc women and children took the offer. It seems likely that Wrex let them keep their Weyrloc traditions and rites.

This very un-Krogan event was another strong signal of change, and further reinforced Urdnot manpower in the long term.

Shepard was soon able to do another favour to her buddy, bringing a very special Krogan with her.


Humans find it difficult to tell Krogans apart. But Wrex had black marks along the right side of his face, which appear to be deep scars left by claws.

Here is a video showing how Wrex speaks and moves – and where he explains the new order on Tuchanka :


During Mass Effect, Wrex is dour, bitter and disillusioned. He apparently tried to do the right thing during much of his youth and always got burnt for it.

Now he wants to be an unattached loner who just enjoys the fights as they come. He doesn’t want to get involved in anything but transient employment. He refuses to associate with anything larger than a small group for a significant duration, and he has to respect them enough for even that to take place.

Urdnot Wrex firing his shotgun on a beach

Wrex is pessimistic, world-weary, fatalistic and fixated on fighting. He sizes up everybody he meets, all the time, and will rarely hesitate to nudge a situation toward a fight. Like all Krogans Wrex really, really likes to fight and his idea of a perfect life is to worry about nothing and get to fight every day before he dies.

While Wrex doesn’t do cheerful, combat-heavy missions with large amounts of gunfire and explosions and biotic warps obviously make him feel content and vital. Krogans in general seem practically addicted to fighting, though Wrex as an individual can reliably rein himself in.

The old man and space

Being centuries old he sees himself as the voice of wisdom. He often offers sarcastic, bitter advice to younger folks in the vague hope of helping them without getting involved in their problems.

Though he’s burnt out, Wrex would like the Krogans to be more than attack dogs. He wants them to transcend their origins and fixations, to think more, and to better themselves. But he’s self-aware enough to know that even he cannot deny his Krogan nature. He sees his species both as fantastic warriors and a hopeless problem for others.

Urdnot Wrex drawing by Stacie Ponder

Krogan culture has numerous features that survived intact from stone age, brutal tribal life. For instance Wrex made remarks implying that regime change is done by killing and eating the previous leaders as a show of strength. The cannibalism might be a symbolic way to assume the authority of the deposed leaders (and not to waste something edible).

Likewise, though the concept is not mentioned in the first game, Wrex might consider himself as one of Shepard’s krantt. This is a sort of champion/bodyguard/comrade-in-arms who brings glory to his leader by showing how seasoned warriors will unquestioningly die in his name.


Despite all his professed cynicism and pragmatism, over the weeks Wrex has come respect, then like, then grudgingly admire Commander Shepard as a warrior, heroine and peacemaker. He also likes her as an idealist.

Despite all his bitterness, Wrex can’t help but see beyond the common “no future, no responsibility and we’re all dead anyway” mindset of most Krogans. He gradually comes to do something very un-Krogan – to trust her.

As mutual respect grows between Wrex and Shepard, a sort of low-key salute spontaneously appear between them. Wrex always greet the Commander with a flat and laconic “Shepard” and she answers “Wrex” in the same tone. Usually this minimalistic exchange isn’t followed by anything and they just resume their activities.

This is a mark of respect between warriors done with a little pomp as possible, though from the oustide it may seem a little strange.

Mass Effect 2

During the second game, Wrex is much less burnt out. He has concluded his long reflexion with Shepard’s help. He now know exactly what he’s going to do no matter what it takes. He’s closer to a King Conan figure and, if he’s successful, may become something of a King Arthur figure.

From his stone throne Wrex negotiates hard, fights hard and does his significant best to change the whole of Tuchanka and manage the redoubtable Clan Urdnot. He goes all out in convincing others to believe in his vision of a Krogan future.

The most shocking aspects of Wrex’s policy — beyond pragmatically building up unexciting resources such as food, water, electrical power, etc. — is to consider violence a second resort rather than the universal solution. A lot of Krogans hate this but it is slowly, painfully working. Those who reject it provide occasion to let off steam and have fights.

Wrex’s attitude is not unlike Shepard’s. He offers an open hand and tries to talk and find mutually beneficial solutions borne by a powerful and charismatic fighter.

Though it has been but two years Wrex projects an impression of being older, wiser, and very hard-working. He’s also a bit more emotionally open, greeting the Commander with a warm “my friend” rather than his flat “Shepard.”


(Dourly) “Anyone who fights us is either stupid, or on Saren’s payroll. Killin’ the latter is business. Killin’ the former is a favor to the universe.”

Commander Shepard: “What about the rest of your family ? Don’t you miss them ?”
Urdnott Wrex (sarcastically): “You tryin’ to make me cry, Shepard ?”

Administrator (yelling to prevent a gunfight between Shepard’s squad and corporate police): “Stop ! Stop ! Everybody stands down ! Let’s not have a fight !”
Wrex (disappointedly): “Why not ?”

Shepard: “C’mon Wrex. You’ve been a merc for 300 years. You must have stories.”
Wrex (dourly): “Well, there was this one time when the Turians all but exterminated us and doomed us to extinction. That was fun.”

“Get back to the Normandy, kid. If you stay out there in the real world you may have to learn something.”

“Krogans are not settlers. We’re warriors. We want to fight.”

“I’m not like you, Shepard. I’m no hero. Bottom line – killin’ for credits simplifies things. I’m tired of sticking my ass on the line and getting nothing for it.”

Staff Commander Shepard : “Can’t the Genophage be cured ?”
Battlemaster Wrex (dourly): “When was the last time you saw a Krogan scientist, Shepard ?”

“Only a fool punches a nathak  in the mouth. We should sneak around and pull its tail.”

“If these executives don’t blame Anoleis for provoking this, they’re fools. You should eat them.”

Game Stats — DC Heroes RPG

Tell me more about the game stats

Urdnot Wrex son of Jarrod

Dex: 04 Str: 06 Bod: 07 Motivation: Fighting
Int: 04 Wil: 04 Min: 06 Occupation: Bounty hunter, merc
Inf: 05 Aur: 05 Spi: 07 Resources {or Wealth}: 005
Init: 014 HP: 040

Biotic barrier: 30, Biotic stasis: 05, Biotic warp: 06, Cold immunity (FF): 01, Damage capacity (FF): 04, Density Increase (FF): 02, Growth: 02, Flame immunity (FF): 01, Regeneration (FF): 04, Sealed systems (FF): 04, Superbreath: 07, Systemic antidote (FF): 05, Telekinesis: 01

Bonuses and Limitations:

  • Growth is Always On and Already Factored In.
  • All Powers with the (FF) tag are Form Function.
  • Superbreath and Telekinesis are both biotic powers.
  • Sealed systems can only prolong how long a Krogan can go without food and water.
  • Superbreath can only be used every other Phase.

Accuracy (Biotics): 05, Charisma (Intimidation): 07, Martial Artist: 07, Weaponry: 06

Area Knowledge (Known galaxy), Familiarity (Zero-G Combat), Iron Nerves, Language (An unspecified Krogan tribal, Council Trade).

Staff Commander Shepard (High), Crew of the SSV Normandy (High), Mercenary scene (Low), Street (Low), Underworld (Low).

None demonstrated.


  • HMWA Master Spectre Assault Rifle [BODY 05, Projectile weapon (Area of effect 0 APs): 10, Range: 07, Telescopic vision: 01, R#02, Advantage: Autofire, Targeting 2, Drawback: Overheat, Limitation: Projectile weapon has No Range, use the listed Range instead]. Wrex’s main weapon, loaded with explosive ammunition.
  • HMWP Master Spectre Pistol [BODY 05, Projectile weapons: 07, R#02, Advantage: Targeting 2, Drawback: Overheat]. Backup weapon, for instance if electronic sabotage makes his rifle overheat.
  • HMWSG Close Quarter Weapon [BODY 07, Shotgun blast (Range 03): 11, R#04, Advantage: Targeting 2, Drawback: Overheat]. Reinforced so it can be used as a club, but seldom used when working with Shepard.
  • RAGE HEAVY BODY ARMOUR [BODY (Hardened) 12 /STR/ 07 /BODY/ 05, Cling: 05, Cold immunity: 02, Flame immunity: 03, Hardening: 02, Joined: 04, Lightning immunity: 05, MEK3 Shield: 20, Radio communications (Booster): 03, Sealed systems: 12, Shade: 03, Skin armour: 04, Medicine (First aid): 04, Recommended STR 06, Limitations: Cling only works on metallic surfaces and reduces movement speed to 0 APs, Medicine (First aid) is Self Only, but works automatically, Skin armour only against Sharp Impact].
    A captured suit of armour built by the Geth for their Krogan mercenaries. This specific suit was repainted to match Shepard’s unit colours and includes kinetic boosters that make the wearer much harder to displace and much more able to displace things (for instance by headbutting them).

Later stats

During Mass Effect 2 Wrex’s INF is 06, and his Charisma Skill now includes the Persuasion Subskill.

By Sébastien Andrivet.

Source of Character: Mass Effect video game trilogy.

Helper(s): Stick figure illustration by Stacie Ponder, from her blog . Model sheet extracted by Troodon80 , and one banner shot by Proboi91 . Improved textures by CDAMJC .

Writeup completed on the 9th of March, 2012.