Photon Grenades. Identical to the grenades fired from the launcher on the pulse carbine, photon grenades are designed to assail the enemy with a sonic blast and an overpowering pulse of multi-spectrum light. They are hurled by hand to confuse and slow enemy closing to hand to hand combat. If a model has photon grenades then enemy assaulting them do not get any bonus attacks for charging. Photon grenades cannot be used with XV battlesuits.
EMP Grenades. EMP grenades briefly emit an electro-magnetic pulse which overloads circuitry, causing fires, meltdowns and other critical malfunctions. They are used when assaulting enemy vehicles. Each attacker may make one attack unadjusted for charging or additional close combat weapons. Roll to hit as normal. When determining damage, roll a D6. On a 4 or 5 they inflict a glancing hit, on a 6 they inflict a penetrating hit. They cannot be used against vehicles with WS that are not immobilised. EMP grenades cannot be used with XV battlesuits.
Honour Blade. This is a long, broad-bladed spear mounted on a lightweight metallic shaft. The honour blade is used to settle disputes between Ethereal caste members in stylised bloodless duels. It is used in elegant sweeping movements where the blade becomes virtually invisible. The honour blade must be used in two hands - the wielder cannot therefore count as carrying an additional weapon. It adds +2 to the wielder's Strength when rolling to wound.
Markerlight.
Range: 36" Strength: n/a AP: n/a Heavy 1
Models use markerlights as a weapon with the above profile instead of using their other weapons, rolling to hit normally. Each markerlight hit can be used to either launch a seeker missile or to mark a target for another vehicle or model. If marking a target then one other vehicle or model in the Tau force which has yet to fire can change its to hit roll against the same target to 2+ with a single weapon (regardless of its BS with that weapon) during the same Shooting phase. Re-rolls for twin-linked weapons still apply to the improved to hit roll.
Errata — Chapter Approved: Codex: Tau Q&A (v2.0): Markerlight hits do not permit cover saves. Markerlights are not searchlights and have no special value at night. A unit that fires at an enemy hit by a markerlight must still be able to draw a line of sight to engage it (unless firing a seeker missile or smart missiles) — this includes checking visibility under the Night Fighting rules if in effect. One weapon may be fired, hitting on 2+, for each markerlight hit.