Gameplay

Last verified 2026-09-24

This page covers every weapon the BRX can fire, how health and damage work, every native game mode and its settings, the classes and perks the Callsign app models, and the Smart Grenade's objective modes.

What the BRX can play

The BRX runs games three ways. You can play from the gun's own menu, with no phone at all. That gives you 7 modes, 5 to 7 stock guns and 9 Supremacy characters. You can play from the Callsign app (14 mode families, a 19-weapon arsenal, QR pickups, perks and killstreaks). Or you can play from a host of your own: that is Open BRX, any rule you can write over hits, teams, health and spawns. All three push the same basics into the same firmware. The gun keeps no game state, so the mode is always whoever is talking to it.

• 19 weapons in the Callsign app arsenal, from 20 captured frames (every one read off the wire)

• 7 gun-menu modes with no phone at all: FFA, Death Match, Generals, Supremacy, Commander, Survival, The Swarm

• 14 mode families built into the Callsign app

• 115 is the default health pool (45 HP + 70 armor)

• 4 native hardware teams (team id is 2 bits in every shot)

• 5 Smart Grenade objective modes, set by a button and a colour

• The arsenal: all 19 Callsign weapons (20 captured frames) with damage, cycle, clip, reserve, heat, reload and fire mode.

• Health, armor and damage: what a hit takes off, what armor does, and why nothing heals on its own.

• How a kill actually works: the 25-bit word of light, the sensors that catch it, the green flash that confirms it.

• Native modes and settings: every gun-menu and Callsign mode, with the exact setting values.

• Classes, factions, perks and killstreaks: Nexus/Resistance/Vanguard, the 9+ characters, the perk row, the streak rewards.

• The grenade's game modes: Frag, Assault, Hill, Respawn, CTF, and how each one really behaves.

Three arsenals, one gun. The gun-menu weapons (M-4, SMG-X3, MG-7, SR-100, TAC-87 and others) are presets the firmware carries for play without a phone. The Callsign app's 19 weapons get sent to the gun over Bluetooth when the game starts. Open BRX sends a third set, its own catalogue, the same way. All three fill the same 6 weapon slots with different numbers, so a gun is only ever running one of them. This page covers the Callsign 19 in full, because we captured every one of them on the wire (20 frames). The five gun-menu weapons are listed from Battle Company's manual. Open BRX's own numbers are balance choices rather than captures, and they live on the arsenal page and Modes and setup, not here.

The complete Callsign arsenal

How to read the numbers. The table has nine columns: Weapon, Role, Damage, Cycle ms, Mag, Reserve, Reload ms, Heat/shot and Fire sound.

• Damage is the raw number the weapon puts in every shot. The target's gun takes this off before any class multiplier applies.
• Cycle ms is the time between shots, in milliseconds. For a charge weapon, it is the charge time instead.
• Mag is the magazine size.
• Reserve is your total spare rounds. The app shows reserve as magazines: mags x clip = reserve.
• Heat/shot is the value the frame's heat token carries. Four weapons set it: SMG 5, Energy Rifle 6, Charge Rifle 14, Plasma Sniper 30. A heat number alone does nothing. A separate token, t38, switches the overheat system on. Callsign sets t38 only on the Charge Rifle, so that is the only stock weapon whose gauge climbs. Open BRX switches it on for the Energy Rifle too.

Hits to kill is not a table column. Find it in the per-weapon notes below. It counts hits against the default 115-point pool (45 HP + 70 armor). It applies only to weapons whose shots land as standard damage on the target's effect table.

Two caveats apply to hits to kill and to Reserve.

• Hits to kill assumes damage does not depend on which sensor is struck. The Head shots row further down answers why it does: $GSET t7 scales a headset hit, and Callsign ships t7 at 50. One Callsign capture showed 18 damage per hit on the headset (sensor 0). The same capture showed 9 damage per hit on the gun body (sensor 4), on the same victim in the same life.
• Reserve is the frame's t17 token: the rounds a Callsign gun gives you. The frame also holds t40, which is always exactly half t17. A bare weapon push leaves the gun holding t40, and its ammo readout mirrors that for about a fifth of a second; the spawn that follows raises it to t17, and that is the count you play with. Measured on the real Assault Rifle frame on 2026-09-18: 96 after the weapon push, 192 after the spawn.

The table below lists every weapon the Callsign app can hand you, with the numbers it actually sends. The search box does a plain text match across all nine columns, so type part of a weapon name, a role or a sound name to narrow the list.

19 weapons come out of 20 captured frames. The 20th frame is the app's unnamed default secondary (T01, 45 dmg, 6-round clip, 4 mags, 0.4 s shell reload). That is the Shotgun itself, slotted as your sidearm before you pick one.

Range is not what the app's bar shows. The app draws a different range bar for each weapon, but the range field in the frames it sends reads the same value (75) on all 18 guns. Melee reads 20. A separate "extra headset range" value shows up on three weapons: 30 on the Shotgun and the Rocket Launcher, 40 on the Plasma Sniper. A garden test on 2026-09-17 found that this range field does nothing outdoors. The other range token, which Callsign sets to the same value (100) on every gun, is the one that matters outdoors, and it does not behave like a distance. In the same garden test a value of 5 landed no shots even muzzle to dome, there was a sharp change between 13 and 26, and every value from about 31 to 100 behaved alike at every distance we could pace.

Stock Callsign hits soft and fast. The standard-damage automatics deal 8 to 15 per hit every 75 to 120 ms. They need 8 to 15 hits, which is about a second of landed fire. The Rocket Launcher, Rail Gun, Laser Cannon and Ion Sniper deal 115: that drops a full-health player in one shot. The two snipers deal 80 every 225 to 300 ms and kill in two hits, in 0.23 to 0.30 s.

Assault Rifle

Assault, full auto, 9 dmg, 100 ms, 32/192, reload 1.4 s. This is the baseline gun. It takes 13 hits to kill, and 1.2 s if every shot lands. (The gun-menu M-4 is printed at 24 damage in Battle Company's manual. The app's Assault Rifle sends 9.)

Burst Rifle

Assault, 3 rounds per trigger pull, 75 ms inside the burst, 275 ms between bursts, 9 dmg, 36/108, reload 1.7 s. One of only two weapons with native burst timing.

Force Rifle

Assault, 3-round burst (100 ms / 250 ms between), 9 dmg, 36/72, 1.7 s. You reload it with a "pull back, let go" motion on the handle.

Bolt Rifle

Assault, single shot, 13 dmg, 225 ms, 18/90, 2.0 s. The rifle with the biggest damage number.

SMG

CQB, full auto, 8 dmg, 90 ms, 72/144, 2.5 s, heat 5/shot. 8 damage is the lowest in the arsenal, so the SMG is the slowest automatic to empty a health pool: 15 hits and 1.26 s, against the Stinger's 8 hits in 0.84 s, the Suppressor's 15 in 1.05 s, the Energy Rifle's 13 in 1.08 s and the Assault Rifle's 13 in 1.2 s. What you buy for that is staying power. 72 rounds is the biggest magazine of any automatic bar the Energy Rifle, nearly five kills without reloading, and the price is the longest reload in the game at 2.5 s (tied with the Charge Rifle). Its heat token reads 5, but the overheat gate is not set, so it never overheats.

Shotgun

CQB, single shot, 45 dmg, 900 ms, 6/12, shell-by-shell reload at 0.4 s per shell. Three hits to kill. It is the only weapon with the "Shells" reload type.

Stinger

CQB, full auto, 15 dmg, 120 ms, 18/36, 1.7 s. The hardest-hitting automatic: 8 hits, and 0.84 s to kill.

Sniper Rifle

Marksman, bolt-action single shot, 80 dmg, 300 ms, 4/12, 1.7 s. Two hits to kill.

Plasma Sniper

Marksman, single shot, 80 dmg, 225 ms, 10/40, 2.0 s, heat 30/shot. The fastest multi-hit time-to-kill in the arsenal at 0.23 s: the 115-damage weapons kill outright in one shot. Its heat token reads 30, the highest number in the arsenal, but the token that switches overheat on is empty in its captured frame, so as Callsign sends it there is no heat lockout. What limits you is the 10-round magazine and the 2 s reload.

AMR

Support, single shot only, 18 dmg, 360 ms, 14/28, 1.4 s. A slow, deliberate pace.

Suppressor

Support, full auto, 8 dmg, 75 ms, 48/144, 2.0 s. Quiet (not silent) and no muzzle flash. It is the only weapon with the stealth fields set.

Energy Rifle

Support, full auto, 9 dmg, 90 ms, 300-round clip, 300 reserve, 2.4 s, heat 6/shot. 300 rounds is the biggest magazine in the arsenal by a wide margin, and 13 hits kill, so that is roughly 23 kills before you reload. Its heat token reads 6, but like the SMG and the Plasma Sniper it ships without the token that switches overheat on, so in Callsign nothing stops the burst except the magazine. Open BRX switches it on: the gun then locks out at about 30 rounds of full auto, and it does not cool by itself, so you work the reload lever to vent the heat.

Charge Rifle

Support, hold to charge and fire when you let go, 100 dmg, 1.25 s charge, 100/100, 2.5 s, heat 14/shot. Two charges kill. Open BRX's own charge rifle is a different weapon: one full charge costs ten rounds of the cell, a tap fires for less, and the kill is one charge plus three taps. It is the one weapon with both a charge-up sound and a release sound, and the one weapon whose overheat gate is actually set, so its heat gauge is the only stock gauge that climbs and locks out.

Rocket Launcher

Power, single shot, 115 dmg (explosive damage type), 1.0 s, 2/4, 1.2 s. A one-shot kill.

Rail Gun

Power, charges and fires itself after about 1.2 s (a tap also fires), 115 dmg (armor-piercing type), 1/3, 2.4 s. A one-shot kill. It has no release sound, because it fires itself.

Laser Cannon

Power, you must hold it to charge, and a tap does nothing. 115 dmg, 1.5 s charge, 4/4, 2.0 s. A one-shot kill.

Energy Launcher

Power, full auto on the wire, but with a 1-round clip every shot is followed by a reload. 115 magnitude, 360 ms, 1/3, 1.4 s. Three spare rounds.

Ion Sniper

Power, single shot, alien-sounding, 115 dmg, 1.0 s, 2/6, 2.0 s. A one-shot kill, with the most reserve in the power tier.

Melee

Melee, gyro swing with the butt of the gun, 90 dmg, 1.0 s, no ammo, no reload. Two swings kill. The hit comes from the front headset emitter.

The firmware has seven fire-mode behaviours, all confirmed on the trigger. Every Callsign weapon uses one of them.

The app's own weapon categories (a UI grouping, not a wire field): Rifle, SMG, Sniper, Shotgun, Heavy, Energy, Support, Power, Exotic, Launcher, Stun, plus Ability and Melee. Nothing the gun receives says which category a weapon is in, so this manual uses a role grouping instead (Assault, CQB, Marksman, Support, Power, Melee).

No stock weapon has an alt-fire. The secondary-fire fields are empty on all 20 captured frames. The orange ALT button cycles perks and abilities in the modes that have them. Every weapon is also just data: a host can send its own weapon into any of the gun's 6 slots, with its own damage, rate, clip, reload, burst, overheat and sounds. That is exactly what Open BRX does.

Battle Company's stock presets below are for phoneless play. The damage scale here is not the Callsign scale above: the printed M-4 says 24, and the app's Assault Rifle sends 9.

Also described in the Extended Guide: the TAR-33 (semi-auto, medium) and a Silenced AR. The two accuracy numbers are that weapon's ceiling and floor: fire fast and your accuracy drifts down from the first number toward the second. A miss still reaches the enemy (their headset lights up and they hear a zip), but they take 0 damage. Fire in bursts, or reload, to bring your accuracy back up. See How a kill actually works for the mechanism.

Health, armor and damage

Every player is a pool of points: 45 health and 70 armor by default, which is 115 in total. A hit comes off your armor first. Whatever armor cannot soak up spills straight into your health. When your health hits zero you are out. Nothing in the stock firmware fills you back up until you respawn.

What happens when you get hit:

1. The shot's damage number lands on your gun. The IR word carries it (see How a kill actually works).
2. Your gun looks up the shot's damage type in its effect table. Most shots are "standard damage". Class abilities can be heals, shield grants or multipliers instead.
3. Armor soaks damage 1 for 1, with no cap per hit. An 80-point standard hit takes all 70 armor and 10 health at once.
4. Health takes the rest. Your headset and gun play the hit tone. The gun reports your new pool to any connected phone.
5. At 0 health the gun plays the death alarm, stops firing, and ignores every incoming shot until it respawns.

Heals and boosts "add", they never "set". When a phone or host gives health to a live gun, the amount is added to your current pool and stops at the maximum. Nobody can set you to a lower number this way, and a grant to a full-health player does nothing. That is why Halo-style regenerating shields, health-on-kill and medic roles all work the same way: a host watches your pool and tops it up.

A dead gun is deaf, unless a station armed it. At 0 health a tagger that was never armed to a respawn station takes no IR at all, and a tagger in a host-driven game takes none either. A tagger armed by a station in a native game is the exception: it stays dead, refuses the trigger, says "revive at respawn point", and comes back the moment the station beacon reaches it.

"Taking damage while in the respawn state is disliked" is a balance note that comes up again and again in the owner community. The gun menu's Ramp 45 and Ramp 90 respawn options grow the wait with each death.

How a kill actually works

A BRX "bullet" is a burst of infrared light 25 bits long, sent on a 38 kHz carrier. It carries who fired (player id), which team, how much damage, and what kind of damage. Your target's headset or gun catches it, looks it up, and takes off the damage. If that was the last of their health, your sight flashes green.

The five steps:

1. Fire. The trigger pull sends the IR word: a 2 ms start pulse, then 25 bits (a long pulse is 1, a short one is 0). Damage type (4 bits), player id (6 bits, 0-63), team (2 bits, 4 teams), damage (8 bits, up to 255), crit flag, effect subtype, 2 check bits.
2. Catch. Your target has five receivers: four domes on the headset, one of them at the back, and a sensor on the gun body. Whichever one catches the word reports it, and the wire tells front from back from gun. Across the field that tells you where the shot came from. At point-blank range the IR floods every sensor, and the first one to see it wins.
3. Resolve. The target's gun checks the team bits first. Same team with friendly fire off means the shot is dropped (one 2026-09-07 bench run registered team hits the other way round and is still unexplained; treat the rule as documented, not proven). Then it looks up the damage type in its effect table and applies the damage: armor first, then health.
4. Feedback. The target's headset flashes green once on a hit, and blinks green steadily while they are out, and plays the pain or death sound. The gun reports the hit and the new health to any connected phone. Melee, explosive and other damage types each get their own hit sound.
5. Confirm. On a kill the shooter's sight flashes green and the announcer says "kill". In a phoneless gun-menu game the guns do this on their own, with no phone involved. In an app-hosted game the phone scores the kill and drives the same flash and voice line.

Why misses still make noise. Every weapon carries a live accuracy model. It has a ceiling and a floor, and you start each life at the ceiling. Keep firing and your accuracy drifts down toward the floor, a bit more with every shot. Reload and you are back at the ceiling. A natural recovery races the drop, so firing slower keeps your accuracy higher: on the harshest setting we tested, single shots about 2 seconds apart held steady one step below the ceiling, while holding the trigger ran it all the way to the floor. How fast it recovers has not been measured. A miss under this model still reaches the enemy: their headset lights and they hear a zip, but the hit carries 0 damage. If someone's headset keeps flashing and they are not dying, you are missing. Fire in bursts, and reload to reset your accuracy outright.

Every shot names its shooter. The 6-bit player id in the word is why a host can credit the exact killer, run free-for-all scoring, and build health-on-kill. All of it comes from what the target's gun reports. Stock BRX uses it too: that is how the kill-confirm and streak callouts find the right gun. The full bit layout, the timings and the effect-table mechanism are in the developer reference.

Native game modes and their settings

The gun's menu gives you seven modes with no phone at all. The Callsign app adds objective play (flags, control points, QR pickups, Battle Royale) plus premium unlocks. Under both, the tagger only fires, gets hit, tracks health and reports. The rules live in the gun menu's firmware presets or in the app.

The mode LED colour shows what you picked. Modes marked with a star are Callsign-Live unlocks on the gun.

(*) = Callsign-Live unlock on the gun.

More than four teams. The hardware supports four native teams, with on-gun friendly-fire protection (subject to the caveat under How a kill actually works) and a per-team LED colour. For more squads, run everyone as one team with friendly fire on. Hand out armbands, and let Mission Control keep the real teams and scores. There is no on-gun friendly-fire protection in that mode.

Starting a gun-menu game:

1. Power on (slide switch by the barrel). LEFT/RIGHT cycle the modes, and the trigger selects.
2. The D-pad picks your team or faction. The trigger cycles weapons or characters. ALT cycles perks.
3. The D-pad sets lives, time, respawn and volume. SELECT moves you on. Your settings stick as the new defaults.
4. Pull the reload handle to start. Headsets pair on their own after power-on (up to about 3 min with many taggers around).

Gun-menu settings, every value:

The Callsign app's modes are the complete list found in the app, with what each one is built from. The app screens group them under categories (Team Arena, Battle Royale, Battle Lines, Faction Wars, Infection) and mode tiles (Arena, Team Arena, Team Snipers, Capture the Flag).

(*) = paid unlock via the app's currency/subscription.

The app's "boxes" are paper. Respawn points, weapon pickups, capture and control points, and supply drops are all printed QR codes you scan or fire at. A weapon pickup simply pushes a new weapon into a slot on your gun. Pickup pool seen in the app: Auto Rifle, Burst Rifle, Sniper Rifle, Shotgun, SMG/SAW, Sticky, Rail Gun, Rocket Launcher, Energy Rifle, War Hammer, Strike Rifle (scoped/unscoped), and "other players".

Callsign GAME SETTINGS, every field on the screen:

Classes, factions, perks and killstreaks

Supremacy swaps the weapon picker for characters. Each one has a fixed gun, a set health/armor/shield build, and an ALT-button ability. Three factions split the roster: Nexus (energy, shields, explode-on-death), Resistance (milsim, explosives) and Vanguard (exotic, long-range).

These are the 9 manual characters, the exact health builds Battle Company prints. There are two pool shapes here: armor characters and shield characters.

Four more classes are described in the Extended Guide but are not in the V7 table:

• Grenadier: laser beam + sticky grenade
• Mercenary: silenced AR + healing/tracking dart
• Valkyrie: burst SMG + mini-rockets
• Sniper: armor-piercing bolt rifle, silencer on ALT

Status effects the app defines: Standard, MedicHeal, ActivateShield, RallyPulse, Radiation (poison), Cryogenic (frost), ArmorPiercing, EMP, Shrapnel, StickyBomb, lethal and non-lethal explosive, ShottyPellets, MeleeDamage, Plasma. Each one has its own hit-sound slot in the app's sound table (poison hit, cold hit, EMP start/loop/end, incendiary start/loop/stop, and others).

Perks are what ALT cycles in Death Match / Generals. Not all games have perks, and TDM is the only stock mode with the perk row.

Killstreak rewards in the Callsign app, from the app's config. None of them is a tagger command.

Post-game medals

21 medals, from the app's config:

• MVP: highest score on their team
• Top Gun: most kills
• Sharp Shooter: most accurate
• Trigger Happy: most shots fired
• Grave Lover: most deaths
• Highest K/D
• Survivalist: fewest deaths
• Top 3: top three score on your team
• The Assistant: most assists
• Objective King: most flags/boxes
• First Blood: first kill of the game
• Double Kill / Triple Kill / Killtacular: 2/3/4 kills, each within 4 s of the last
• Streaky: a 5-kill streak
• Streakerten: a 10-kill streak
• Streakernaut: highest streak in the game
• Ninja: 3 melee kills in one life
• Assassin: most melee kills
• Weapons Expert: 3 kills with 2+ weapons
• Head Shot: 5 kills by head shots only

The Smart Grenade's game modes

The BRX Smart Grenade is more than a bomb. Hold its button and it turns into a portable objective: a respawn station, a King-of-the-Hill point, an assault objective, or a CTF flag base. It talks to every gun in range with an IR beacon, and the guns make the sounds. There is no app for this. You set the mode on the device itself, and it stays locked there.

Setting a mode (the finicky part, exactly):

1. Turn the grenade off, then on, and wait for the green LED (that means ready).
2. Hold the top button for about 4 s: a long loud beep means you are in setup.
3. It beeps fast and cycles colour while you hold. (A tagger left in its own setup mode says each mode's name as you cycle, which is a free audio monitor.)
4. Let go on the colour you want. The LED turns white to confirm the lock.
5. The mode survives a power-cycle. On boot it flashes the current mode's colour for about 1 s so you can check it.

The Respawn-station catch that earns the grenade its "buggy" reputation. Setting the grenade to Respawn is not enough. Each tagger must also receive the station's IR to switch from self-respawn to station-respawn. Either show every gun the station before the game, or press the grenade's button near each gun after the start (the reliable way). A gun that never got the signal just self-respawns as normal.

Where the grenade sounds come from. The detonation, the flashbang and gas effects, the CTF music, "control point captured": all of it plays from the gun and headset, triggered by the grenade's IR. The grenade itself only chirps and flashes for status. Swap the tagger's sound files and every grenade "sounds" different, without touching the accessory.

Beyond stock: what a host can add

The gun keeps no game state, so any rule you can write over hits, teams, health and spawns is a mode, and the host that runs it does not have to be Battle Company's app. That is what Open BRX is: a laptop and a phone per player, running rules the tagger never had to know about. The modes it runs, what each one needs and which have been played on real taggers are on the Open BRX modes page; the wider catalog of mode designs lives in the repository, in docs/game-modes.md.

The grenade as a control point

A control point is a place on the field a team can own: a King of the Hill point, a Domination point, a bomb site. A Smart Grenade in Hill mode is a complete one on its own. No phone, no host, no app, and it works in native games. You shoot it to capture it, and nothing else on the BRX does that.

Everything below was measured on the bench.

• Capture is by charge, not by shots. Any weapon can take a point, and the attacker wins ties. One Assault Rifle round took a neutral point; about four rounds' worth of charge took one an enemy team was holding.
• It beacons its owner every 5 seconds to every gun in range, and it changes colour and beeps, so everyone nearby knows the moment it flips.
• It holds its owner with nobody standing there. Ten straight beacons on one owner, with no one shooting it.
• Ownership travels only over IR, and only a gun receives IR. So nobody learns that a far point flipped until a player walks into range. Reception is solid close in and intermittent by about 30 feet, with dropouts of 85 and 145 seconds measured at the edge.
• One beacon carries no point id, so two grenades cannot be told apart on the wire. That caps you at one usable point per game.
• A non-capturing hit emits nothing we can decode, so a contested point is not a state anything can read. Downed players on the point are invisible to it too.
• A beacon is unauthenticated.

The hill chips you, and that is measured. An unattended enemy hill killed a player in about 106 seconds, 8 damage every 5 seconds, with no host involved. In a native game that is the mode working: it punishes standing on someone else's point.

Do not put a player on team 2 in a hill game. A neutral hill broadcasts team 2. The gun's own filter compares that against the gun's team, so a player on team 2 reads every neutral point as already theirs and takes no hill damage. Use teams 0, 1 and 3. That consequence follows from two measured facts and has not been tested directly.

What it costs. We paid about $200 for our Smart Grenade, from Battle Company. Read that as what was paid rather than as a current price: retail moves, it varies by region, and it is one purchase.