Do not ask "Why Kill the Alien?", rather ask, "Why not?"
Deathwatch is the third in the Warhammer 40000 roleplaying game series. While Dark Heresy focuses on agents of the Inquisition, and Rogue Trader focuses on rogue traders and their crew, Deathwatch casts the players as Space Marines of the Ordo Xenos Deathwatch, a sort of special operations group tasked primarily with defending humanity from alien horrors. Even among the Space Marines, the Deathwatch are considered to be an elite unit — and when the typical Space Marine is a seven-foot tall Super Soldier with a standard-issue fully-automatic grenade launcher and armor that can stop a tank shell, that's pretty impressive.Now think about what you're going to be up against...Six Chapters are included in the core rulebook, five of which already exist in the Warhammer 40,000 canon: the Space Wolves, Ultramarines, Dark Angels, Black Templars, and Blood Angels. According to the blog, these particular Chapters were chosen to create stark contrast in tactics and personalities within the party between members of different Chapters (though the fact that they're also 40k's flagship Chapters, each with its own codex, probably doesn't hurt). The sixth Chapter, the Storm Wardens, are an original creation of Fantasy Flight Games; the lessons the dev team learned in creating this Chapter are expounded upon in the Rites of Battle supplement, so you can have a go at creating Chapters of your own, you special snowflake, you.See also Dark Heresy, Rogue Trader, Black Crusade, Only War, and of course Warhammer 40000.
This game provides examples of:
Abnormal Ammo: Deathwatch Tactical Marines are issued boltguns with a dual-magazine system and a fire selector that allows them to switch which magazine the chamber is fed from. Typically, one magazine will use standard rounds, the other will have specialized rounds for combating specific kinds of threats. These are the same kinds of special rounds which are normally only issued to Sternguard Veterans in their home chapters, but no marine comes to the Deathwatch who is not already experienced and distinguished among his chapter peers.
The Ace: Deathwatch really hammers home that this is the Ultramarines' hat. Not only do the Ultramarines get a bonus to interactions with other Imperial soldiers because of how well-respected they are, but their Chapter-specific Squad Mode abilities are both based on the Ultramarine's Fellowship — meaning that a Kill-team that includes an Ultramarine will actually fight better because he has a Ph.D. in being handsome and wonderful. What a guy!
This is taken so far that the Ultramarine's Primarch's Curse (caused by getting too many Insanity points) actually causes the Ultramarine in question to lower squad cohesion if he ISN'T put in charge.
Ascended Meme: Mark of the Xenos gives stats for greater daemons, and each entry begins with a relevant quote. The quote for the Lord of Change entry?
The Atoner: Black Shields are generally this, Marines who join the Deathwatch and keep their home chapter a secret. Perhaps because the chapter has fallen and they are the Sole Survivor, hoping to go out in glory. Or a Marine who was kicked out of his chapter for some failure, hoping to redeem themselves in the Deathwatch.
Badass Bookworm: Dark Angels characters, in addition to being Stone Walls, are also this, since their chapter-specific advances have the most options for Scholastic Lore and Forbidden Lore out of any core chapter.
Badass Crew: Deathwatch characters get squad-based abilities that improve their effectiveness while they're working together as a cohesive unit.
The Berserker: Blood Angels characters tend towards this, unsurprisingly. Their Chapter-specific abilities revolve around hitting better and harder in melee, and taking fewer Wounds by virtue of simply not feeling any pain.
The Flesh Tearers (a Blood Angels successor Chapter given rules in Rites of Battle) are even worse; with the right combination of talents and wargear, they can bring down boss-level monsters in one or two rounds of combat, simply due to the insane bonuses they get from charging and the raw power their many MANY attacks provide.
BFG: Oh Lord, yes. A Space Marine's bolt pistol sidearm actually deals more damage per shot than the heavy bolters available to Dark Heresy and Rogue Trader characters, and it goes up from there. (This discrepancy is justified in-universe by saying that these guns were originally designed for the Space Marines in the first place, and that everyone else in the Imperium is using knock-offs scaled down for ordinary human use.) Errata 1.1 introduces alternate weapon rules that scale the bolters back a bit — and make several of the Marines' other guns even nastier.
They STILL out-damage mortal heavy bolters even after the errata...but only by 1 point of damage.
BFS: The Sacris Claymore, signature weapon of the Storm Wardens, is a sword big enough that a Space Marine, a seven-foot tall killing machine that can bench press a truck, needs two hands to wield it effectively. The Power Claymore described in Rites of Battle is basically the same thing with a power field wrapped around it, and the Relic Blade is an even bigger and nastier version of that. It's also worth noting that every Space Marine's standard-issue combat knife deals more damage than the basic swords available to most other folk (or at the very least the same amount of damage, if using the optional weapon rules from Errata 1.1).
Black Knight: Rites of Battle details the "black shields", Astartes who forsake their Chapters of origin and dedicate themselves to the Deathwatch.
Bling of War: Chapter Trappings of various sorts, which have in-game rules effects, and Honours, which are primarily a roleplaying device.
Brave Scot: The Storm Wardens chapter of Space Marines (original to this system) recruit exclusively from a world populated with Scotland-esque highland warrior clans IN SPACE.
Bug War: Deathwatch characters are likely to find themselves in the middle of one of these, courtesy of the Tyranids. Examples include the free quickstart adventure, Final Sanction, and the introductory adventure given in the core rulebook, Extraction.
Character Alignment: The Demeanour system is a variation on the concept. Each marine will have a certain set of core values indoctrinated into him by his chapter, representing one core Demeanour, and an additional Demeanour which is specific to him as an individual. These exist partly as roleplaying aids, but a character who is acting "in-character" with a particular Demeanour can trigger that Demeanour once per session, and gain bonuses by doing so. If the roleplaying of it is particularly well done (subject to other player's approval) those bonuses are increased. In this way the player is incentivized to roleplay effectively and leverage that roleplaying to invoke a personal Crowning Moment Of Awesome.
Cool Gate: One of the main objectives of the crusade into the Jericho Reach (the main setting of the game) is to secure a warp gate that leads to the other side of the galaxy. Conveniently, this also allows Deathwatch to cross over with the default campaign settings for Dark Heresy and Rogue Trader, despite the literally astronomical distances between them.
Enemy Mine: The Achilus Crusade was originally intended to drive the Tau from the worlds of the Jericho Reach. Following the arrival of Hive Fleet Dagon in the Reach, certain Imperial commanders and Tau leaders have suggested temporary alliances in order to stand against the Tyranid threat. The Tau Commander Flamewing exemplifies this mindset.
Evil Counterpart: Most of the foes that a kill-team will face are either hordes of weaker enemies that they will have to push through, or smaller numbers of very powerful enemies that they must overcome with cleaver teamwork. However, kill-teams operating in the Acheros Salient for any length of time will sooner or later run into Chaos Space Marines, who can match the kill-team for combat potential. In a setting where battle-brothers are expected to be powerful paragons of war, foes who are so similarly skilled and equipped make for a unique and deadly challenge.
Fearless Fool: The fear rules of the system are still in place, but Astartes react to them differently than other characters. Confronting a horrific foe might reduce their willpower a bit, or make working as a team more difficult, but it will never cause them to flee in terror, feint, or abandon their duty. However, a kill-team who is counting on an Imperial Guard company for backup against a terrible enemy might have to deal with suddenly find their backup absent at an inopportune moment...
Fire-Forged Friends: The rules are structured with the assumption that a starting Kill-Team will have been just formed, with each Player Character freshly seconded to the Deathwatch from their home chapters. As they work past their differences in ideology and combat style and learn to work effectively as a team, the Cohesion mechanic comes into further prominence, allowing their mutual trust and knowledge of each other to execute impressive bonus maneuvers that none of them could accomplish singly.
Firing One Handed: This has always been possible in the system, but Deathwatch makes it practical. Astartes Power Armor negates the normal penalty for firing a basic-class weapon (a longarm) with one hand instead of two. This is pretty essential for any character using a single Power Fist or Lightening Claw, as those weapons preclude holding another weapon with that hand.
Foe Tossing Charge: An Assault Marine with the right Talents (Thunder Charge, Whirlwind Attack, Preternatural Speed, Lightning Attack, Wrathful Descent) can easily perform one, annihilating an entire Horde within a five-second turn of combat.
The Jerico Crusade is like this. They thought they found a few a few xeno-corrupted worlds, then it turned out to be a powerful Tau base. They thought they were facing a few scattered heretics and then it turned out there was a massive Chaos presence. Then the Tyranid hive fleet showed up. Then, as of the latest expansion book, a whole Necron empire is waking up well behind the front lines with the power to take all the other factions on at once...
General Ripper: Lord Commander Sebiascore Ebongrave, leader of the Canis Salient of the Achilus Crusade fighting the Tau across the Greyhell Front. He rose to his position after the previous Canis Salient Lord Commander was assassinated by a Tau-sympathizer at the same time that xenophile organized rebellions hit several Imperial worlds that the Crusade had already conquered and assumed secure. Trying to avoid his predecessor's fate, Ebongrave began a great program to purge the population of xenophiles, aggressively propagandize the Imperial anti-Tau cause, and eliminate any potential Tau-sympathizer's from his own staff. Unfortunately, as forces have been diverted to deal with more pressing threats of the Tyranid incursion and the Imperial offensive against the Tau have ground to a stalemate, his normally commendable zealous hatred of xenos and their sympathizers has gone into full paranoia. He sees Tau conspiracy all around him, resulting in brutal crackdowns on planetary populations and public executions on even the merest rumor. Members of his own staff who suggest brokering a cease-fire with the Tau to better deal with more pressing threats are quickly reassigned to the front line or executed, resulting in Imperial forces being tied down and occupied in a demoralizing quagmire of a conflict.
Government Conspiracy: As first mentioned in Dark Heresy, the Margin Crusade, a war of faith driven by the Ministorum into the Halo Stars from the Scarus, Calixis and Ixaniad sectors, which continues to this day but has made little progress and contact with those sent to it is inevitably lost. However, Deathwatchreveals this crusade to have been largely a lie all along, as a way of getting resources into the Achilus Crusade. The presence of the warp gate between the Segmentum Obscurus and the Jericho Reach is a closely guarded strategic secret, and thus the pretext was needed to get the necessary forces mustered without the information of it being leaked. Even most of the people fighting and dying in the Achilus Crusade know not for what they are really fighting, believing themselves to be sent on a holy war for the Ministorum.
The Hero: While all Space Marines are heroic (in the classical sense, if nothing else), Tactical Marines fit the trope best. Their abilities tend to skew towards leadership and command, with a secondary role as the Jack of All Stats.
Heroic Sacrifice: There's even a mechanic for it. A Marine can forfeit his last 'get out of death free' ticket (Fate Point) to receive about a minute's worth of near-invincibility after which he's irrevocably dead.
Highly Visible Ninja: Most battle-brothers are actually fairly skilled at remaining unseen and silent, as most chapters will have them serve in scout companies before being elevated to full battle-brothers, in addition to being trained to carefully spot other's hiding for potential ambushes. However, while wearing Astartes Power Armor, a battle-brother receives significant penalties to his ability to hide or move quietly due to the bulk of his armor and the noise it makes while moving. Any battle-brother trying to stay undetected will fall squarely into this unless he takes great pains beforehand to wear something other than his iconic armor.
Hopeless War: The Achilus Crusade seemed quite promising when it began as a military venture to re-take Imperial worlds that had been isolated for a few millennia due to warp storms, where re-established Imperial control would form a buffer against the Tau Empire's expansion into the sector. When Lord Millitant Achilus' ship suffered a geller field failure in-warp, the crusade was split into three fronts, but fate was not kind to the new strategy:
The forces earmarked to combat the Tau now find themselves commanded by a man who routinely purges his officer ranks for xeno-sympathizers and refuses to allow forces to be transferred away, pushing into Tau space with a commendable but poorly-timed zeal. He attributes the lack of progress on this front to Tau conspiracy to subvert the forces under him and incite planetary populations to rebellion, when in fact his heavy-handed crackdowns still his efforts as much as any Tau influence does.
And did we mention that the base of the Deathwatch is a Necron Tomb-World, with its inhabitants already stirring? Because that seems important.
Hunting the Most Dangerous Game: The heretek Magos Phayzarus from Mark of the Xenos takes this a step beyond the norm, hunting Space Marines in order to consume their precious gene-seed. This is a majorBerserk Button for any Space Marine worth the title.
Iconic Item: Normally equipment must be requisitioned from the Deathwatch armory and surrendered to the quartermasters after missions. The Signature Gear talent allows a character to keep a particular piece of wargear on hand as "theirs" rather than going through the normal requisition channels. Purchasing this talent multiple times allows items of greater rarity to be kept, expanding the amount of wargear available to a battle-brother when they do requisition.
Implacable Man: Any battle-brother wearing Terminator armor becomes this, having protection equivalent to a force-field that never overloads, plus one of the highest armor ratings available, gaining strength even above what is normally available to Astartes Power Armor, and allows heavy weaponry to be fired singled-handedly. It restricts the wearer from running, imposes a penalty to his agility, makes him incapable of dodging attacks, requires the highest levels of renown, and has a truly staggering cost in requisition for both the armor and a separate mandatory amount of weapons.
Incorruptible Pure Pureness: The Astartes themselves are expected to play this very straight. The Corruption mechanic in the system is still in play, but Astartes will not suffer its negative effects until crossing the final threshold at which point they are considered "fallen" and will be dealt with swiftly and harshly. However, an Astartes who gets more than a handful of corruption points will be looked on with deserved suspicion by his peers, and the rulebook advises the GM to give them out when they need to remind the players of who their character's are and what is expected of them.
Jack of All Stats: The Ultramarines, as usual. While Marines of other Chapters get to add a bonus to two specific abilities, Ultramarine characters get to pick which two abilities to improve.
Leave Him to Me: The Storm Wardens' Thunder's Call ability allows them to invoke this against a single enemy per combat. The rest of the Kill-team is generally expected to kill everyone else in the room while the boss is occupied.
Lightning Bruiser: The Assault Marine — strong and tough as any other Space Marine, able to make two melee attacks straight off the bat, and thanks to his Jump Pack, very, very fast.
Magic Knight: The Librarian character class is this in a nutshell. While they are spell casters with plenty of offensive and utility power, they are no more squishy than any other Astartes, walking around in full Power Armor and trained in physical combat as much as they are in psychic combat.
The Medic: The Apothecary, whose abilities mainly center around healing and boosting the performance of his Kill-team. Can also learn to create toxins. Kind of subverted in that Apothecaries are no more squishy than other Space Marines.
Military Science Fiction: More so than the other two 40k roleplaying games, since characters in Deathwatch are specifically intended to engage in military operations and deal with military-grade threats.
More Dakka: Devastator Marines. Much like a well-built Assault Marine, a well-built and well-equipped Devastator Marine can destroy an entire Horde of enemies in a single turn (though the latest round of errata has scaled this back significantly).
The Hadex Anomaly, a warp/real space overlap created centuries ago by some massive act of ritual sorcery. Time flows differently in there, and as a result Chaos-held worlds there can have a generation born, grown, trained, and formed into warbands in only a few years of objective time, which negates the Imperium's primary resource advantage, and ensures that the fighting in the Cellebos Warzone is particularly bitterly fought just to maintain a stalemate.
The Black Reef is an area of strange gravity disruptions that makes faster-than-light travel more dangerous the closer to it one goes. It forms a natural divide between Imperial controlled space on one side, and Tau controlled space on the other. Both sides must go around the Reef rather than through it, forming a chokepoint for both factions. Due to differences in the way that they use FTL travel, the Tau can approach closer to it more safely than the Imperials can, but their slower travel limits that advantage.
One-Man Army: Deathwatch Kill-Marines, introduced in the Rites of Battle supplement, are specialists trained to perform solo missions without the support of their battle-brothers.
The Paladin: The player characters are this exclusively. Astartes are indoctrinated to be above certain mortal concerns, and one who deviates too seriously from this is going to be looked on with suspicion by his battle-brothers. In addition, each chapter has its own particular sets of values and ideals for how an Astartes should behave, adding diversity to how this trope is played.
Sanity Slippage: The insanity mechanic of the system affect's Astartes differently than it does other humans. Rather than being affected by more random psychosis, increasing insanity points manifest in a battle-brother as a kind of exaggeration of the negative stereotypes associated with their respective chapter. This is know as the Primarch's Curse. How they learn to live with it is the measure of a veteran Space Marine:
Black Templars become increasingly fanatical about their hatred for psykers, making interaction difficult and potentially going against better judgement to try and slay them, even if the mission says otherwise.
Dark Angels become more aloof and self-isolating, becoming paranoid about others trying to pry into their secrets, distrusting all except other Dark Angels.
Space Wolves become more savage in their appearance and manner, disturbing others, get overpowered by the scent of their enemy's blood, and have difficulty backing down from a fight, even when a Tactical Withdrawal would be the best option.
Storm Wardens have difficulty managing their thirst for glory, and exaggerates their tendency to place Honor Before Reason, refusing to back down from a challenge and trying to fight "fair" even when victory would be more important their their personal honor.
Ultramarines feel increasingly convinced that they are the Imperium's favored sons, making sure that the kill-team goes where the fighting is thickest, and become convinced that others cannot be trusted to do what is "right" in all circumstances, eventually refusing to follow the leadership of anyone other than another Ultramarine.
Scarily Competent Tracker: Space Wolves get bonuses that lend themselves well to tracking and infiltration, filling an advanced scout role.
Shout Out: The Deathwatch writers are not shy about reaching out to other works in the franchise:
The basic rulebook has a quote from Commissar Holt of Warhammer 40,000: Final Liberation fame.
The Expanded Wargear chapter in Rites of Battle has an opening quote also from Commissar Holt.
Stone Wall: Dark Angels characters tend towards this, with abilities that trade movement ability for heightened defenses, temporary Wounds and improved firing capabilities.
Their Librarians even get a psychic power that lets them essentially become an actual stone wall, with massive amounts of armor as long as they don't move.
Suicidal Overconfidence: Normally a video game trope, it is notable in this instance because the rulebook clearly advises the Game Master to not imitate the trope when running a tabletop game like this. The Deathwatch characters are more powerful than others from this setting, and virtually everyone they go up against will know it. It reminds the GM that even the most fanatical of foes who are eager to die for their cause will still want to sell their lives as dearly as possible, and thus will be more likely to commit only from a position of strength rather than charge out to die without at least a chance of threatening the kill-team.
Take Up My Sword: Astartes Power Armor is difficult to manufacture, even for the Astartes, as each piece of it must be carefully crafted by artisan Tech-Marines. As a result of this difficulty, components from the armor of fallen marines end up being recovered and reused in new suits of armor provided to freshly raised battle-brothers. Many chapters develop elaborate rites and practices around this process, engraving pieces with the history of its wearers, and this is reflected in the armor of Deathwatch kill-teams. Each player must roll on a table to determine the history of their armor, and this history will give the armor its own set of (literal) mechanical quirks.
Teeth-Clenched Teamwork: While not every Deathwatch kill-team has this issue, it does come up with Kill-teams formed of Astartes drawn from chapters with significantly different traditions. For example, the enmity between the Dark Angels and the Space Wolves is well known, Black Templars are likely to balk at having to work with a Librarian, and an Ultramarine is likely to have friction with any marine from a chapter that does not take the Codex Astartes as seriously as he does. As some Black Library books have commented, learning to reconcile the different traditions between chapters in the Deathwatch is one of the more unique challenges a Space Marine may have to contend with. Honour The Chapter presents several more examples, such as a rivalry between the Space Wolves and the Blood Ravens due to the latter's excessive use of psykers (as the Wolf Lord demonstrated to the Blood Raven Captain with a punch in the face).
Twisting the Words: Kill-teams operating in the Acheros Salient are known to come across quotations from the Codex Astartes, written in blood near the scene of a massacre by Word Bearers Chaos Space Marines. These quotations are deliberately taken out-of-context, twisting the meaning to imply justification for their gruesome actions. They do this purely to spite the Astartes who find it.
Up to Eleven: Deathwatch is this to the other Warhammer 40,000Table TopRole Playing Games. Especially combat mechanics, where Player Characters start at the highest end of the power scale for the other ones and only go up from there. However, no matter how powerful the Kill-Team is, they will always be going up against foes at least one step up from that, some of whom are so powerful that the Battle-brothers will be forced to rely more on their wits, guile, and teamwork to triumph rather than their prodigious combat strength alone.
Visible Invisibility: Masking Screens, small devices attached to the shoulder which dampen the wearer's noise and project an active-camouflage effect on their armor. They are reverse-engineered from the cloaking generators captured from Tau stealthsuits, but being unable to completely reproduce them without the "xenos-taint" makes the technology imperfect, only modestly improving a battle-brother's ability to hide over the brightness and noise of his armor and imposing a penalty to his perception of objects outside the narrow effect of the screen.
Walking Tank: The Rites of Battle supplement allows for player characters to be interred in Dreadnoughts. However they have to be near death and of high level and renown.