Rules

This section has been designed loosely along the lines of a standard GW Codex Army List.  However, it is not only utterly unofficial but only slightly play-tested and very much a Work In Progress.  This is far from the only version of a Codex: Arbitrators you'll find online and some of the best of the rest can be found in the Roll of Honour.  In addition, there are a few ways of fielding an Adeptus Arbites Precinct within the existing range of official GW Codexes.  You'll find hints and tips on fielding an "official" Precinct force under Within the Law.

Special Rules

Armoury

HQ

Elites

Transport

Troops

Fast Attack

Heavy Support

Arbitrator Special Rules

Arbitrators  The Adeptus Arbites is a tiny force by comparison to the threats they must face.  What they lack in strength of numbers and power of arms, they make up with disciplined coordination of forces and an intimate familiarity with their ground and environment.  All Arbitrators carry an encrypted, shielded comm-link that allows them to share information and communicate directly with their commanders from any part of the battlefield.

Arbitrator units may use the Ld of any other Arbitrator unit on the table to make Ld checks.  This is still modified as normal for outnumbering etc.

Leaders  Some unit special rules will depend upon who the designated Leader of the Precinct is in a particular battle.  One and only one HQ character must be designated as the Leader of the Precinct.

Single-Handed Weapons

Double-Handed Weapons

Equipment

Vehicle Upgrades Table

Items marked with an * may only be taken by Judges or Marshals.

Items marked with an † may only be taken by Judges.

Arbites bike  The Arbites bike is similar in design to its counterpart, the Space Marine bike, but slightly smaller to allow for it to be used by normal-sized humans.  The rules for bikes can be found in the Warhammer 40,000 rule book.  Arbites bikes are equipped with twin-linked bolters.  A Judge or Marshal on a bike may not be accompanied by an S-Court.

Arbites combat shotgun  The signature weapon of the Adeptus Arbites is a terrifying weapon.  More accurate than a normal shotgun, it is also specially adapted to fire the deadly Executioner rounds.  It may be fired in either Combat or Executioner mode each turn, but all models with Arbites combat shotguns in a squad must fire their weapons in the same mode in the same turn.

*Executioner rounds may re-roll missed shots.  Note that no miss may be re-rolled more than once.

Arbites grenade launcher  Arbitrators, unlike conventional military forces, normally operate many non-lethal weapons.  When facing a serious opponent, they leave most of these in the armoury, but they have developed battlefield tactics that make use of grenades other than the conventional frag and krak.  As a result, Arbitrators armed with grenade launchers may use frag and krak grenades as normal, but may also fire a smoke grenade with the following profile:

Smoke grenades do not cause wounds.  Instead, if the grenade successfully hits its target, in the target unit's next turn it counts as moving in Difficult Terrain.  Smoke grenades have no effect on vehicles.

Cyber-mastiff  Senior investigators and officers of the Adeptus Arbites often take a personal cyber-mastiff to the battlefield.  It must always stay in base contact with its owner and fights the same opponent(s) as him.  If the character loses his final wound while the cyber-mastiff is on the table, roll a D6.  On a 4+ the cyber-mastiff is destroyed instead.  The cyber-mastiff counts as an auspex and fights with the profile given below:

Hunter Mount  Hunter Mounts may be specially-trained horses, vicious native riding beasts or merely equipped with barbed or electrified attachments.  A model riding a Hunter Mount gains the Fleet special rule if he does not already have it and also gains +1 A.  A Judge or Marshal riding a Hunter Mount may not be accompanied by an S-Court.

Power armour  Comprising cybermuscular bundles that enhance the wearer's strengtha and agility, encased in ceramite and steel plates, this armour is amongst the most advanced protection the Imperium can offer.  A Judge wearing power armour gains a 3+ Armour save.

Redemption Pack  Exclusively issued to Martyrs, the Redemption Pack is a generic term to describe an explosive waistcoat.  It may be remotely detonated or user-detonated, but in any case it can be as much a threat to its own side as to the enemy!  When the Martyr is activated as described in the Army List, place the Ordnance template over the place the Martyr finishes his rush.  Models covered by the template take an automatic Strength 8 AP 2 hit.  Partially-covered models are hit on a 4+.

Riot shield*  Usually used in conjunction with the shock maul, the riot shield is a three-quarter-length shield that incorporates a small refractor field generator.  Not as powerful as a full refractor field, it can nevertheless slow low-velocity blows to harmlessness.  The shield can also release its field charge in a single electrical jolt, similar to the effect of the shock maul.  Riot shields may be used in the Assault phase to either count as a close combat weapon or to confer a 2+ save against close combat attacks only.  All models in a unit, including independent characters that have joined the unit, must use their riot shields for the same function in any given turn.

Rosarius  The rosarius is a token of good faith given by the Ecclesiarchy to high-ranking allies.  It confers the holy blessing of the God-Emperor on its bearer and, entirely by coincidence, also incorporates a powerful refractor field.  Models equipped with a rosarius have a 4+ invulnerable save.

Searchlight  The use of hand-held searchlights is common amongst Arbitrators hunting criminals.  A squad equipped with a searchlight may use it when the rules for Nightfighting are in effect.  They may shoot normally at one enemy unit.  However, all enemy units may shoot normally at a unit using a Searchlight in this way.

Shock maul  The shock maul is a baton-like hand weapon that delivers a powerful electric shock to its target that can stun or even kill.  The shock maul counts as a close combat weapon with the Rending special rule (see Warhammer 40000 rulebook).

*Traditionally, Arbitrators have carried "suppression" shields.  However, Codex: Witch Hunters has given the rules of suppression shields such that they confer a 4+ invulnerable save and count as a close combat weapon.  This is fair enough for 1-3 Crusaders in an Inquisitor's retinue, but do you want to see a whole squad of such monstrosities?  No, neither do I.

Headquarters

Judges are amongst the most powerful figures in the Imperium.  Few in number, they are members of the Emperor's Bench - official advisors to the High Lords - and responsible for the maintenance of the Dictates Imperialis within vast areas of space known as Judicial Demesnes and may have several space-borne precincts of combat-ready Arbitrators at their disposal.

Equipment A Judge may take equipment from the Precinct Armoury.

Options The Judge and his S-Court, if he has one, may be mounted in a Rhino, a Chimera or a Repressor for the Points values listed in the Transport section.

Special Rules

Independent Character  Unless accompanied by an S-Court, Judges are Independent Characters as described in the Warhammer 40,000 rulebook.

Arbitrator  Judges are Arbitrators as described in "Arbitrator Special Rules", above.

Judicial Demesne  Judges are not themselves powerful warriors, but the resources at their disposal are almost unlimited.  If the Judge is the Leader of the Precinct (see Arbitrator Special Rules), then the Arbitrator player may ignore the 0-1 restriction on Custodians and may take Elite choices as either Troop choices or Elite choices.  However, there may only ever be one Judge in any army, even in an army with more than one detachment.

Marshals are the leaders of Adeptus Arbites planetary and sector precincts and can bring the resources of a whole precinct to bear against an enemy.  All too often, however, despite their advanced armour and weapons, they find themselves outnumbered and outgunned.

Equipment A Marshal may take equipment from the Precinct Armoury.

Options A Marshal may be upgraded to a Marshal Senioris for +10 points.  The Marshal and his S-Court, if he has one, may be mounted in a Rhino, a Chimera or a Repressor for the Points values listed in the Transport section.

Special Rules

Independent Character  Unless accompanied by an S-Court, Marshals are independent characters as described int he Warhammer 40,000 rulebook.

Arbitrator  Marshals are Arbitrators as described in "Arbitrator Special Rules", above.

Call for Back-Up  If the Marshal is the Leader of the Precinct (see Arbitrator Special Rules), then the Arbitrator player may always keep any number of units as Reserves even when the scenario does not normally allow Reserves to be used.  Reserves will enter the battle as described in the Warhamer 40,000 rulebook.

Judges and Marshals are often accompanied to the field by a body of trusted staff  known as a Special Court of Prosecution, or "S-Court". 

Squad  A Marshal may have an S-Court of 1-4 Advisors.  A Judge may have an S-Court of 3-9 Advisors.

Equipment  Advisors count as being armed with a laspistol and close combat weapon unless indicated below.

Options  Advisors may be upgraded with any of the following options:

• Judiciary (+4 points) Deeply knowledgeable in the ways of the Lex Imperialis, a Judiciary will ensure that all the commander's actions are in-line with precedent and tradition.  The commander may re-roll one Ld test per turn.  Note that this re-roll cannot be used by units using the Arbitrators special rule.

• Mechanicus Lex (+4 points) The Adeptus Mechanicus provide limited integral support to the Adeptus Arbites.  These junior tech-priests manage orbital satellite networks and maintain precinct armouries.  The squad may re-roll a single to-hit roll per turn.

• Chirurgeon (+4 points) Many leaders are ancient, sustained only by extensive surgery and rejuvenat drugs.  Their systems require constant monitoring by a dedicated chirurgeon who can also step in to apply bandages to fresh wounds.  The commander and his S-Court may ignore the first wound from shooting that does not cause Instant Death per turn.

• Psykanus Lex (+6 points) The mysterious Precinct Psi provides elite psyker-Arbitrators to advise and assist Precinct leaders.  The commander counts as being equipped with an auspex.  In addition, the unit receives a 5+ invulnerable save against the effects of all psychic powers.

• Bodyguard (+10 points) Bodyguards protect their commander from attack.  They may exchange their weapons for a bolt pistol and shock maul.  In addition, one bodyguard in the S-Court may swap places with the commander at the start of any Assault phase, before charges are made.

Benefits from Advisors last only as long as at least one Advisor of each type survives in the S-Court.

Elites

All Arbitrators are trained in the use of the shock maul and riot shield, but only a few are so adept that they will be formed into special assault Shock Teams when the Precinct goes to battle.

Squad  The Shock Team consists of 5-10 Arbitrators.

Equipment  Arbitrators are armed with shock mauls and riot shields.

Options  One Arbitrator may be upgraded to a Proctor for +6 points; he may take equipment from the Precinct Armoury.  One Arbitrator may swap his shock maul for an Arbites Grenade Launcher (+5 points).  The entire squad may be mounted in a Rhino, a Chimera or a Repressor for the Points values listed in the Transport section.

Special Rules

Arbitrators  Shock Teams are Arbitrators as described in "Arbitrator Special Rules", above.

Shield Wall  By interlocking their shields, a Shock Team can give themselves limited protection against ranged fire.  If all members of a Shock Team are in base contact, they receive a 6+ cover save.  All models in the squad benefit from this save, even if they are not equipped with riot shields.

Executioners are specialists in shock tactics and provide the most visible and terrifying example of the Emperor's wrath to those who choose to disobey the Lex.

Squad  The Execution Team consists of 5-10 Executioners.

Equipment  Executioners are armed with bolters.

Options  One Executioner may be upgraded to a Chastener for +6 points; he may take equipment from the Precinct Armoury.  Up to three Executioners may swap their bolters for an Arbites Grenade Launcher (+5 points), plasma gun (+4 points) or flamer (+3 points).  Up to three Executioners may swap their bolters for a Heavy Bolter (+10 points) or a Missile Launcher (+8 points).  One Executioner who is not carrying a heavy or special weapon may be equipped with a searchlight at +1 point.  The entire squad may be equipped with frag grenades for +1 point per model.  The entire squad may be mounted in a Rhino,, a Chimera or a Repressor for the Points values listed in the Transport section.

Special Rules

Arbitrators  Executioners are Arbitrators as described in "Arbitrator Special Rules", above.

Infiltrators  If they do not have a squad transport and the scenario rules allow, the team may Infiltrate as described in the Warhammer 40,000 rulebook.

The Adeptus Arbites routinely employs snipers against criminals and their marksmen are amongst the best outside the Officio Assassinorum.  Part of their strength is in the employment of paired teams of snipers and spotters, who help guide the sniper to exactly the right target.

Squad  Each selection on the Force Organization chart may include 1-3 Sniper Teams.  All the teams must deploy at the same time but otherwise count as separate units.

Equipment  The Sniper is armed with a needle sniper rifle.  The Spotter is armed with an Arbites combat shotgun.

Options  Spotters may take an auspex for +3 points each.

Special Rules

Arbitrators  Snipers are Arbitrators as described in "Arbitrator Special Rules", above.

Infiltrators  If the scenario rules allow, Sniper Teams may Infiltrate as described in the Warhammer 40,000 rulebook.

Eyes and Ears  The Spotter feeds a constant stream of information and corrections to the Sniper, helping him find the perfect shot.  As long as the Spotter is on the table and does not fire in the Shooting phase, the Sniper may ignore normal rules for target selection.

Buddies  The Sniper Teams work as pairs, with each looking out for the other.  If either is unable to continue, the other will drag his buddy to safety.  If either member of a Sniper Team is killed, at the end of the turn remove both.  If one survives, the team only counts for half Victory Points in a scenario counting VPs.

There are many possible fates for a criminal in the Imperium.  Imprisonment, death, service in the Penal Legions, lobotomization... When enemies threaten, a Marshal may authorize the extraordinary psycho-conditioning of condemned prisoners to offer them a final chance at redemption before they stand before the Emperor's throne.

Squad 1-3 Martyrs.

Equipment  Martyrs counts as being armed with a laspistol and close combat weapon, plus a Redemption Pack.

Options  Nil.

Special Rules

Not independent  All the Martyrs from a single choice in the force organization chart must be attached to the same Auxiliary Platoon.  They may not join any other unit.  Martyrs in a platoon count as members of that platoon for all purposes, with the exception of For the Emperor! (below).

For the Emperor!  A Martyr may be deployed in any Shooting phase as long as the platoon is not locked in combat (in other words, even when the platoon is otherwise pinned or unable to shoot).  Move the Martyr 6" in any direction (towards the nearest enemy is usual) and then roll D6" scatter.  This is the point at which the Martyr will detonate.  Remove the Martyr and treat him as a casualty for the purposes of Victory Points, morale checks and suchlike.  The Martyr may not deploy from an Auxilliary Platoon that is falling back.

Troops

The Patrol Team is the basic unit of the Adeptus Arbites Precinct.  Tough, resourceful and dedicated, they can nevertheless find themselves outmanoeuvred and outgunned on the unfamiliar territory of a battlefield.

Squad  The Patrol Team consists of 5-10 Arbitrators.

Equipment  Arbitrators are armed with either Arbites combat shotguns or bolters.  These weapons cannot be mixed in one team.

Options  One Arbitrator may be upgraded to a Proctor for +6 points; he may take equipment from the Precinct Armoury.  One Arbitrator may swap his shotgun or bolter for a grenade launcher (+3 points), flamer (+3 points) or plasma gun (+4 points).  One Arbitrator who is not carrying a special weapon may be equipped with a searchlight at +1 point.  The entire squad may be equipped with frag grenades for +1 point per model.  The entire squad may be mounted in a Rhino,, a Chimera or a Repressor for the Points values listed in the Transport section.

Special Rules

Arbitrators  Patrol Teams are Arbitrators as described in "Arbitrator Special Rules", above.

Custodian Team  One Patrol Team per precinct may be made a Custodian Team for +4 points per unit member.  Custodian Teams are the ceremonial guards of a precinct's Courtroom.  They typically carry the Precinct's finest weapons and have earned their place in the team through long years of faultless law-keeping.  Custodian Teams ignore all negative modifiers when making Ld tests.

Auxiliaries sometimes reinforce the Arbitrators, like it or not.  They may be local police forces, conscript PDF, penal troops, press-ganged civilians or released prisoners.  They are poorly trained and badly disciplined, but they are plentiful and cheap.

Squad  4-19 Auxiliaries, plus an Arbitrator leader.

Equipment  The Arbitrator leader is armed with either an Arbites combat shotgun or a bolter.  Auxiliaries carry a mix of weaponry but whatever items the models are holding, they count as being armed with a laspistol and close combat weapon.

Options  None.

Special Rules

Arbitrators  The Arbitrator leaders are Arbitrators as described in "Arbitrator Special Rules", above.  As long as the unit has at least one Arbitrator leader alive, they benefit from this rule.

Safety in numbers!  Up to three Auxiliary platoons in the same detachment may be joined together.  They still count as separate selections on the army organization chart but in all other respects are then counted as a single unit.

Keep the scum in line  Auxilliaries are insufficiently disciplined to perform a fighting withdrawal efficiently and inevitably there will be those who are left behind, cut down in the rush or eliminated by the leaders to encourage compliance.  If an Auxiliary Platoon fails a Ld check then as well as following the usual rules for falling back, they take as many casualties as they failed the Ld check by.  If several Platoons have been joined together usinn the "Safety in numbers" rule, then they lose that many casualties per Platoon.

Fast Attack

Bikes are a routine part of the Adeptus Arbites' patrol assets but few Arbitrators have the skill to join the elite ranks of the Venators.  Deployed onto the trail of important fugitives, Venators are expert trackers, able to live and work in the field for months on end, doggedly bringing their quarry to bay.

Squad  The Pursuit Team consists of 3-5 Venators on bikes.

Equipment  Venators are armed with Arbites combat shotguns and their bikes are equipped with twin-linked bolters.

Options  One Venator may be upgraded to a Venator Major for +6 points; he may take equipment from the Precinct Armoury.

Special Rules

Arbitrators  Pursuit Teams are Arbitrators as described in "Arbitrator Special Rules", above.

Scouts  If the scenario rules allow, Pursuit Teams may deploy as Scouts as described in the Warhammer 40,000 rulebook.

Move through terrain  Pursuit Teams roll one more D6 than usual when determining how far they can move through Difficult Terrain.

Rangers are most often encountered on more primitive worlds and on newly-colonized planets, where they are often employed far from the centres of authority.  Even in more advanced cultures, the intimidating presence of armoured Outriders and their massive mounts can be a force multiplier in confrontation situations.

Squad  5-10 Rangers on horses (or local equivalent).

Equipment  Rangers are armed with Arbites combat shotguns.

Options  One Ranger may be upgraded to a Ranger for +6 points.  The Proctor may take equipment from the Precinct Armoury.  All members of the squad may exchange their shotguns for riot shields and shock mauls for +10 points each.  All members of the squad may upgrade their mounts to Hunter Mounts, aggressive creatures trained to fight in concert with their riders, for +6 points.

Special Rules

Fleet of hoof  Outrider Teams are Fleet as described in the Warhammer 40,000 rulebook.

Heavy Support

Arbitrators operate near-impregnable fortresses, bristling with armaments but, away from these, they are lightly armed and have few heavy weapons at their disposal.  They do, however, maintain batteries of platform-mounted heavy weapons intended to provide semi-mobile point-defences at roadblocks.

Squad  The Defence Battery consists of 3 weapon teams consisting of 2 Arbitrators each.

Equipment  Arbitrators are armed with Arbites combat shotguns.

Options  Each battery must be armed with either 3 Rapier Laser Destroyers for +150 points, or Tarantula Sentry guns for +60 points.  Tarantula batteries may upgrade their twin-linked heavy bolters for twin-linked lascannons for +30 points.

Special Rules

Weapon Teams  Each weapon requires at least one of its surviving crew to operate.  Randomize hits on the battery: 1-4 crew, 5-6 weapon.  The weapons count as vehicles with an armour value of 10.  Any glancing or penetrating hit will destroy the weapon.

Cumbersome  The weapon platforms are not designed for high mobility.  The unit may not move and shoot.  In addition, they roll only 1D6 to move through difficult terrain and may not make Assault moves.

Battle tanks are not routinely a part of the Adeptus Arbites peace-keeping forces, but sensible precincts will maintain at least one Leman Russ as a weapon of last resort to be deployed against mass uprisings and major incursions where support from the PDF for local Imperial Guard garrisons cannot be relied upon.

Options  For options, see Codex: Imperial Guard.  The Leman Russ may take upgrades from the Precinct Armoury Vehicle Upgrades table.

Roll of Honour

Kendoka - Magnus "Kendoka" Johansson is seriously obsessed and is almost certainly the owner of the world's largest Adeptus Arbites precinct.  His rules are a lot of fun with a lot of character, but don't go here for game balance!  This document is a PDF and you'll need Adobe Reader to download it.

Seigeworld - Rather less colourful, but more restrained than Magnus's version, I'm not sure who's behind this PDF, but it seems to owe debts to many of the same sources as my own.  Quite a few clever ideas can be found in these rules and I think I've pinched the best of them

Within the Law

There are basically two schools of thought within the community of those who use the Adeptus Arbites in games of Warhammer 40,000.  The "Space Marine Scout" and the "Witch Hunter".  Both approaches will yield armies with distinctive characters that are completely tournament legal.  However, be warned: using these armies means accepting substantial restrictions on troop choices that will severely reduce the player's options and tactical flexibility.  These are challenging armies.  In other words, expect to lose more often than you win.  On the positive side, if you do use these armies as a tournament army, you can expect great "army composition" scores!

The "Space Marine Scout" Precinct

This list variant has enjoyed varying popularity over the years.  The prevalent argument tends to revolve around whether the Adeptus Arbites should or should not have access to powered armour but, ultimately, this is the list favoured by those who see the Arbites as super-guardsmen, with better equipment, better armour and better training.

HQ Choices - Space Marine Commander, Chaplains or Librarians can all count as Judges in powered armour and a command squad can be taken as an S-Court.  But steer clear of Terminator armour - the Arbites just aren't that well equipped!  Feel free to mount your HQ in a Rhino.

Elites - Techmarines can be taken to count as especially tough Techpriests allied with the Adeptus Arbites and some players even use the Dreadnought stats to count as judicial riot servitors.  No venerable dreads, though; no Terminators or Veterans, either.

Troops - The principle choice here is Scouts, Scouts and more Scouts.  Arm them with needle sniper rifles for Sniper Teams, with shotguns for Patrol Teams and with bolters and heavy bolters or missile launchers for Execution Teams.  At all costs, resist the temptation to take Tactical Squads.

Fast Attack - Scout Bikers are the main source here, but Land Speeders can also be taken.  However, Land Speeders will need to be cunningly converted to enclose their pilots and gunners, because Arbites don't wear power armour!  Fortunately, Space Marine Land Speeders don't count as "open topped".

Heavy Support - Land Raiders may seem a bit advanced for the Adeptus Arbites, but a mobile Precinct Fortress is a Courthouse on wheels.  If you can convert something to look less like a Land Raider, everyone will be impressed.  No Devastators and no Vindicators, though.  The jury's still out on Predators.

The "Witch Hunter" Precinct

This is a very popular list to use as an Arbitrator Precinct and is growing in currency to the point that these are starting to be, if not common, then at least not jaw-droppingly rare at tournaments.  You will still certainly enjoy considerable kudos if you get one of these to a tournie.

HQ Choices - Stick with the Inquisitor Lord as your Judge.  The favoured retinue is three Crusaders, counting as a mini Shock Team, but all of the usual options are as appropriate to a Judge as they are to an Inquisitor.

Elites - Death cult assassins make good Detectives - elite, lone agents with the best kit and the ability to infiltrate behidn enemy lines.  Officio Assassinorum assassins will work across the board.  A Vindicare would be the most "fluffy", but, ultimately, who's counting?  Avoid the Sisters of Battle throughout, with the exception of Sisters Repentiae: these represent a really crazed Legio Penitanti rather well, I think.

Troops - The definitive choice is the Inquisitorial Stormtroopers squad, re-equipped with shotguns as in the Designer's Note by the army list entry.

I have written an Army List of this sort, using Allied Space Marines in Troops, Fast Attack and Heavy Support.  You can see the list here.  As I get around to buying, building and painting the models, I'll put up links to the pics as well.