Pathfinders are the main scouting infantry forces for the Fire Caste of the Tau Empire. As light reconnaissance units, Pathfinder Teams are the eyes and ears of their Tau Commander in a way no Tau Drone can yet emulate. A Pathfinder's role is not to engage the enemy, but instead to maximise the efficiency of the rest of their Hunter Cadre with their Marker Lights which designate priority enemy targets and guide the fire of their comrades. Pathfinders often operate ahead of the main body of Tau forces and close with the foe to accurately scout the enemy. In such a position, a Pathfinder's life is always under threat. For this reason and more, Pathfinders are held in high regard by the member of every Tau caste.
Compared to standard Fire Warriors, Tau Pathfinders have a more specialised role on the battlefield and possess incredible long-range reconnaissance capabilities. They are the eyes and ears of a Hunter Cadre, although they coordinate closely with other Tau formations as well. Pathfinders are the undisputed masters of battlefield positioning, possessed of limitless patience and a proud determination to choose the most valuable targets for their fellows to destroy. Pathfinders stand at the front to guide their comrades' aim, and not to win the battle themselves. In other words, an efficient Pathfinder Team helps its fellow Fire Warrior teams operate at their peak efficiency. This concept of working for the Greater Good (Tau'va in the Tau Lexicon) at the expense of personal glory is the guiding light of all Tau activity. Their embodiment of this basic philosophy makes Pathfinders highly popular with their fellow Tau warriors and earns them enormous respect in Tau society.
Utilising anti-gravitic Devilfish troop carriers, Pathfinder Teams range far ahead of the rest of the Hunter Cadre in search of enemy forces. They maintain a close watch on the foe while remaining expertly hidden, reporting details of the enemy's nature and disposition by way of highly encrypted, nigh-undetectable communication systems. Pathfinder Teams are also deployed in the role of aggressive patrol groups, maintaining dominance over a wide area around an otherwise stationary Hunter Cadre and detecting any enemy forces that attempt to approach. Occasionally, an entire Hunter Cadre of Pathfinders is tasked with a mission, such as exploring a newly-discovered planet and ascertaining if it is suitable for Tau colonisation. By infiltrating the battlefield before a confrontation, Pathfinders can also activate Homing Beacons or Positional Relays -- bringing reinforcements to the fray with greater precision.
Pathfinders are equipped with a range of specialised equipment to aid in their mission, and though they are not protected by a Tau Battlesuit or stealth field generators, they are far from helpless. A Pathfinder's standard kit includes a Pulse Carbine fitted with an underslung Photon Grenade Launcher as their primary weapon -- ideal for the close-ranged firefights they so frequently find themselves engaged in. The blinding, disorienting effect of the Photon Grenades is utilised by the Pathfinders when reacting to sudden and unanticipated contact with the enemy.
Every member of the team also carries a Marker Light, a laser designator device attached to his weapon that projects an all-but-invisible, highly-focused beam of coherent light at a potential target. Every Marker Light is networked to support weapon platforms and other units on a Tau battle network, and transmits precise targeting information in order to guide the fire of such units and increase their accuracy. When used to guide the armour-piercing Seeker Missiles carried as additional weapons on many Tau main battle tanks, aircraft, spacecraft or fixed installations, Pathfinders are able to remain hidden as they call in devastatingly powerful and unerringly accurate missile artillery fire onto the target. Many Imperial troops have come to fear the small, red dot of light that appears on the body of those about to be slain, and Imperial troops who fought in the Damocles Gulf Crusade described the signature of the barely visible Marker Light beams as the "Valkyrie's Mark", because those it chose were soon numbered among the dead. Often the first indication of imminent contact with Pathfinders is the telltale red dot of a Marker Light appearing upon an enemy warrior's armour, followed an instant later by a barrage of Seeker Missiles. On many occasions, Pathfinder Teams hold back while observing an infiltrating force, only calling in fire when their enemy is too far forward to extricate safely.
When fighting on the frontline standard Fire Caste doctrine, as laid down in the Code of Fire, instructs all warriors to fight closely together, with each member of a team doing his utmost to protect not just his comrades, but also nearby teams in his Cadre. Through the use of overlapping fields of fire, Pathfinder Teams can also provide supporting fire and help annihilate the enemy.
While every Tau Sept has tales of crafty Pathfinders escaping from impossible odds, even the best-laid extraction plans can fall through. Trading lives for ground is anathema to the Tau, and the warriors of the Fire Caste are trained to retreat and fight another day. All Tau warriors are willing to lay down their lives for the Greater Good, but Pathfinders find self-sacrifice called for more often than all other Cadre teams combined. Holding a Marker Light on a distant enemy while your own position is being overrun is a selfless act, but Pathfinders epitomise the Greater Good, and by their actions, many battles are won. During the early days of the Great War of Confederation, some Septs reported Pathfinder casualty rates at 84% or higher. Despite this, or perhaps because of it, the Fire Caste academies are inundated by volunteers wishing to be Pathfinders, eager to do their utmost for the Greater Good.
- Pathfinder Search and Destroy Cadre – Specialised detachments of rapid-moving, highly manoeuvrable units operating forwards of mainline Hunter Cadres to reconnoitre and disrupt enemy movements and destroy targets of opportunity have proved their worth to the Fire Caste time and time again. Such Pathfinder Search and Destroy Cadres are formed around the most skilled Tau Pathfinder Teams, who serve to direct and control their Cadre's actions, providing Marker Light guidance and selecting which targets should be concentrated on by the Cadre's sudden attacks. The formation's main fighting force is comprised of DX-6 Remora Drone Stealth Fighters that excel in conducting high speed hit-and-run attacks and rapid flanking manoeuvres. The Remoras work to disrupt and scatter enemy troops whilst singling out and destroying targets of strategic importance, such as command vehicles and support units with their heavier armaments. The Cadre's eyes and ears on the move will often be Tetra scout speeder teams who range ahead of the Remoras and Devilfish to relay battlefield data. In combat, Pathfinder Search and Destroy Cadres are continually on the move, hunting down their prey and attacking targets before moving swiftly on. A Pathfinder Search and Destroy Cadre will always consist of at least one Pathfinder Team mounted in a Devilfish, at least one Remora Drone Fighter team, and at least one Tetra scout speeder team. A single Devilfish in the Cadre will usually be designated as the command tank.
- "Mirage" Long Range Infiltration Unit – Tau Pathfinders are often dropped behind enemy lines on embattled worlds many solar days before a major Tau offensive as a "Mirage" Long Range Infiltration Unit. These night-time infiltration missions are highly risky, as the team is often completely isolated because it is forced to maintain communications silence for many days, deep in enemy territory. Only their powerful stealth fields allow them to remain undetected for so long as they identify the key objectives in the enemy defence lines. When the primary Tau assault begins, the main role of these teams is to use their Marker Lights to direct the devastating firepower of the main force against the chosen targets. A "Mirage" Long Range Infiltration Unit formation will usually consist of one to three Devilfish-mounted Pathfinder Teams, along with an attached Stealth Optimised Devilfish that carries a powerful stealth field generator which disguises nearby comrades within its radius of effect. All Devilfish in a "Mirage" formation will also have their Gun Drones replaced with Marker Drones, to better aid the Pathfinders in highlighting enemy targets.
A typical Tau Pathfinder squad will number from four to ten Shas'la members, usually led by a Shas'ui veteran and bonded together by the ritual of Ta'lissera. A typical Tau Pathfinder is equipped with a Pulse Carine for use as his primary weapon, along with an attached underslung Photon Grenade Launcher and Marker Light. Photon Grenades are also issued as standard weapons to Tau Pathfinders, though some teams have been known to carry EMP Grenades for use against vehicle threats. All Tau Pathfinders are protected by a lighter form of the standard Combat Armour employed by Fire Warriors known as Recon Armour. Recon Armour sacrifices a degree of protection for greater freedom of movement and better stealth capabilities. A Pathfinder Shas'ui will often have additional hard-wired combat systems cybernetically implanted into his body or integrated into his armour as his rank allows, and these can include systems usually found only on Tau Battlesuits, such as a Blacksun Filter, a Target Lock or a Multi-Tracker
Up to three Pathfinders in a team can replace their Pulse Carbine and Marker Light with either a Rail Rifle and Target Lock, or a Ion Rifle. These special weapons add much needed heavy firepower and are capable of eliminating threats such as heavy infantry and light vehicles. Rail Rifles are relatively new and powerful armour-piercing weapons that are an infantry-portable form of larger Tau Rail Weapons, whilst Ion Rifles are an even more recent addition to the Pathfinder's arsenal. An Ion Rifle is able to fire in two distinct modes -– a stable shot that vaporises light vehicles, and an overcharged mode that is unstable but causes more explosive damage across a small area.
Many Pathfinder Teams employ Tau Drones as additional support, and typically up to two Drones -- which can be either Gun Drones, Shield Drones or Marker Drones -- will be attached to a Pathfinder squad. As of the time of the Third Sphere Expansion, several new Drone variants specially designed to assist Pathfinder Teams have been developed and are sometimes seen being field-tested in battle. These Drones include Grav-Inhibitor Drones, Pulse Accelerator Drones, and Recon Drones.
Most Tau Pathfinder Teams make use of specially modified Devilfish transports to aid them in getting into and out of position during their missions. These Devilfish can also provide supporting heavy firepower if necessary. Devilfish assigned to Pathfinders will be equipped with a Marker Beacon -– a variant of Marker Light technology that is used to designate a position to which jump troops and orbital insertion craft can be guided, allowing units such as Tau Battlesuit teams to drop directly onto their target. Pathfinders sometimes use Tetra speeders as a light and fast transport in place of a Devilfish, and this allows them to get into position far ahead of a Hunter Cadre before dismounting and continuing on to their targets on foot so as to remain undetected. Once the reconnaissance mission has been completed, they will return to their speeders and race back to their own forces
- Codex: Tau (3rd Edition), pp. 28, 62
- Codex: Tau (4th Edition), pp. 28, 38
- Codex: Tau (6th Edition), pp. 32, 38, 101
- Imperial Armour Apocalypse (2nd Edition), pg. 85
- Imperial Armour Volume Three – The Taros Campaign, pp. 178, 283
- Deathwatch: Mark of the Xenos (RPG), pp. 24-25
- Games Workshop Website - “Mirage” Long Range Infiltration Unit Apocalypse Datasheet