Custom Bots

What's New in v5.0.0

Version 5.0.0 is a ground-up overhaul of every major system. The combat engine was rebuilt with triple line-of-sight verification. The decision engine now evaluates all actions simultaneously instead of using priority chains. Training AI uses validated navigation circuits. Every stat scales logarithmically with round progression.

Combat Engine Overhaul

• Triple LOS Verification — Every shot checks centroid, feet, and final aim point. If any check fails, the bot stops shooting entirely. No more shooting through walls.
• Reaction Jitter — Each new target acquisition adds random variation (±50ms) to reaction time, preventing the robotic consistency that makes AI obvious.
• Focus Accuracy — When a bot stays locked on the same target, aim scatter tightens by 15% after 1 second and 25% after 2 seconds. Simulates real players "locking in" on a target.
• Weapon-Class Burst Fire — LMGs spray long continuous bursts. Shotguns fire 1–2 precise shots. SMGs burst 4–8 rounds. Snipers take 1–3 careful shots. Each weapon class feels authentic.
• Magazine-Aware Training — Before turning to shoot during a train, bots check their clip. If below 30%, they reload first instead of turning with 2 rounds left.
• Directional Flee — When overwhelmed, bots calculate the zombie cluster's center of mass and flee directly away from it, preferring paths that break line of sight.

Decision Engine Overhaul

• Utility AI Scoring — Every tick, all possible actions (combat, revive, flee, buy perks, buy weapons, use box, PaP, open doors, grab powerups, train) are scored and ranked. The highest score wins.
• Dynamic Perk Priority — Quick Revive gets +200 when a teammate is downed. Speed Cola gets +100 when using an LMG. Perks adjust to the situation instead of following a static list.
• Max Ammo Awareness — If a Max Ammo powerup is sitting on the ground, bots skip ammo purchases entirely to save points.
• Anti-AFK Leader — Bots track each human's velocity. If a human has been stationary for 10+ seconds, bots reduce their desire to follow that player by 50%.
• Smart Early Weapons — Instead of buying the nearest wallbuy, bots score available weapons and pick the best affordable one. They prefer the M14 over the Olympia.
• Launcher Avoidance — Launchers, RPGs, and War Machines receive a score of -999, effectively blacklisted. AI and splash damage don't mix well.
• Resource Lock Safety — All resource locks (Box, PaP, debris) are automatically cleared when a bot dies or enters last stand, preventing permanent lockouts.

Positioning & Navigation

• Smart Dodge — When blocking a player's path, bots step perpendicular to the player's movement direction instead of teleporting to a random point. Looks like a natural "step aside."
• Rank-Scaled Stuck Detection — Shotguns bots detect they're stuck after 2.5 seconds. Bones bots get 4.5 seconds of tolerance. Higher-ranked bots react faster to navigation problems.
• Door/Debris Stuck Prevention — After 4 seconds of no movement toward a door goal, the goal is automatically cancelled and a different action is selected.
• Elite Early-Game Skip — Rank 3+ bots skip the window-camping phase at round 3+ and go straight to opening doors. Elite bots don't waste time.

Round Scaling

• Logarithmic Curve — Stats improve via 0.10 * log2(round), capped at 0.40 around round 16. Fast improvement early, diminishing returns later.
• Elite Scaling (R40+) — A secondary linear factor of (round - 40) * 0.005 (capped at 0.15) kicks in for headshot chance, crowd flee count, and powerup range. Keeps bots viable through round 70+ without breaking early balance.

Communication & Safety

• Randomized Callouts — 4+ variants per status category ("LOW AMMO" / "RUNNING DRY" / "NEED AMMO" / "ALMOST EMPTY") so bots sound like different personalities.
• Dynamic Headshots — Uses the j_head bone tag for accurate headshots on crawlers (lower head), standing zombies, and tall bosses (higher head).
• EE Health Gate — If a bot drops below 30% health during an Easter Egg objective, the goal pauses for 3 seconds so combat and flee systems can take over.
• Revive Danger Scaling — Bots without Juggernog use a lower danger threshold (4 vs 8 nearby zombies) before attempting revives. No more suicide revive attempts.

Why Custom Bots

BO2 Zombies is designed for 4 players. Solo, you miss out on revives, the points economy is tighter, doors take forever to open, and Easter Eggs that require multiple players are impossible. Existing bot mods either give you bots that stand in corners doing nothing, or they follow you like shadows with no independent thought.

Custom Bots solves this by creating AI teammates that actually play the game. They don't just react to what you do — they make their own plans.

Before vs. After

Installation

Installation takes less than 30 seconds. You need Plutonium T6 installed on your PC. If you don't have it, download it from plutonium.pw and follow their setup guide first.

File Paths

%LOCALAPPDATA%\Plutonium\storage\t6\scripts\zm\custom_bots.gsc

Quick Start

No configuration is needed. By default, the mod spawns 3 bots at Shotguns rank (the highest tier) the moment you start any Zombies map. This fills your lobby to 4 players (you + 3 bots), which is the intended player count for BO2 Zombies.

The bots will immediately begin playing: buying weapons at wall locations, defending windows in the early rounds, knifing zombies for bonus points, opening doors when they have enough money, buying perks, and scaling their behavior as rounds progress.

Want to customize? Open the in-game console (~ tilde key) and type any command from the Configuration Reference.

Common Scenarios

set bo2_zm_bots_rank "bones"
set bo2_zm_bots_count 1

set bo2_zm_bots_ee 1
set bo2_zm_bots_rank "shotguns"

set bo2_zm_bots_count 7

Configuration Reference

All settings are DVars (dynamic variables) entered in the in-game console. Press ~ (tilde) to open the console, type the command, and press Enter. Every setting has a sensible default — you never need to change anything unless you want to.

DVars persist for the current Plutonium session. If you want settings to apply every time, add them to your Plutonium configuration file.

Core Settings

Feature Toggles

Set to 1 to enable (default) or 0 to disable.

Cosmetic Settings

Console Examples

set bo2_zm_bots_count 2         // Two bots instead of three
set bo2_zm_bots_rank "skull"    // Mid-tier difficulty
set bo2_zm_bots_ee 0            // Disable Easter Egg assistance
set bo2_zm_bots_callouts 0      // Disable chat callouts
set bo2_zm_bots_name_prefix ""  // No prefix (just the name)
set bo2_zm_bots_clan "AI"       // Change clan tag

Rank System

Every bot is assigned a rank that controls over 35 behavioral parameters. Ranks mirror the BO2 Zombies ranking icons and represent a spectrum from helpless to superhuman. The default rank is Shotguns (highest tier) because most players want competent teammates.

Rank doesn't just change accuracy — it affects everything: how quickly bots react, how well they dodge hazards, whether they can train zombies, how aggressively they push for weapons, and how reliably they revive teammates.

Rank Capability Matrix

Autonomous Decision Engine

The decision engine is the brain of every bot. Every tick (approximately every 0.25 seconds), the engine evaluates all possible actions simultaneously and picks the one with the highest score. This is a utility AI system — not a priority list, not a state machine, not a behavior tree.

The key insight is that every action competes on the same scale. A revive opportunity scoring 1200 will always beat a perk purchase scoring 400, but a perk purchase scoring 400 will beat a routine roam scoring 50. Context changes scores dynamically: the same action can score 100 in one situation and 600 in another.

Action Scoring Overview

Dynamic Score Modifiers

• Point Reserve — Supportive bots maintain a 1500 point buffer for emergencies. Purchase scores are reduced when the bot would drop below this reserve.
• Weapon-Quality Urgency — Holding a pistol at round 10+ massively boosts Mystery Box and PaP scores. The bot knows it needs a real weapon.
• Cost-Aware Scoring — Expensive purchases are penalized when the bot is low on points. A 3000-point perk might score lower than a 1500-point wallbuy if the bot only has 4000 points.
• Round Pressure — PaP urgency scales exponentially in higher rounds. By round 20, the decision engine strongly pushes bots toward upgrading their best weapon.
• Personality Bias — Aggressive bots boost weapon, box, and PaP scores. Supportive bots boost revive scores by +200. Cautious bots boost perk, ammo, and flee scores.
• Ammo Emergency — When ammo drops below 10% of max capacity, ammo buy scores jump to 600 (urgent). Below 25%, scores are 300–500.
• Max Ammo Awareness — If a Max Ammo powerup is on the ground, ammo buy scores drop to 0. No point wasting money when free ammo is available.
• Smart PaP Selection — Bots don't just PaP their current weapon. They evaluate all held weapons and upgrade whichever one scores highest based on damage, magazine size, and fire rate.
• Launcher Blacklist — Any weapon with "launcher," "smaw," "rpg," or "war_machine" in the name receives a score of -999. AI bots and splash damage are a bad combination.
• Debris Lock — When a bot targets a door or debris, it's locked to prevent other bots from trying to buy the same one. Lock clears when the purchase completes, fails, or the bot dies.

Advanced Combat Engine

The v5.0.0 combat engine was rebuilt from scratch with one goal: bots should never shoot through walls, and they should feel human when they fight. Every aspect of target acquisition, aiming, and firing is controlled by rank-scaled parameters that produce realistic combat behavior.

Target Acquisition

When scanning for targets, bots evaluate all zombies within their weapon's effective range. Each potential target receives a composite score based on distance (closer = higher), clustering (splash weapons prefer groups), threat level (zombies running at teammates get priority), and line-of-sight quality. The highest-scoring target is selected.

A reaction jitter of ±50ms is added to every new target acquisition. This prevents the perfectly consistent snap-to-target timing that makes AI bots obvious. Combined with rank-based reaction time (800ms for Bones, 50ms for Shotguns), the result is targeting that looks human.

Focus Accuracy System

Real players get more accurate the longer they track a target. Custom Bots simulates this with a focus timer. When a bot stays locked on the same zombie:

• After 1 second — Aim scatter reduces by 15%. The bot is "dialing in" its aim.
• After 2 seconds — Aim scatter reduces by 25%. Full focus achieved.
• On target switch — Focus timer resets. The bot has to re-acquire its precision.

Weapon-Class Behavior

Firing Discipline

• Range-Gated Firing — Maximum engagement range is 450 units (reduced from 600). Drops to 300 at 50% ammo, 200 at 25%. Bots won't waste ammo on distant targets that aren't threats.
• Ammo Conservation — Conservation activates at 60% ammo (not 40%). Range suppression kicks in at 350+ units even at full ammo (25% shot skip). Burst sizes capped to 2-3 shots at range. Pause between bursts doubled when low on ammo.
• No Scatter at Close Range — Within 150 units, aim scatter is completely removed. Direct aim at the zombie. Scatter only applies at distance where it simulates natural aiming variance.
• No Fallback Shooting — If the final aim point fails line-of-sight verification, the bot stops shooting entirely. No "shooting at the wall hoping to hit something."
• Dead Target Cutoff — Right before every trigger pull, the bot re-checks if the target is still alive. If the zombie died mid-burst (killed by another player or trap), the bot instantly stops firing. No more shooting at corpses or empty air.

Smart Grenades

The T6 engine's built-in bot grenade system is completely disabled (bot_AllowGrenades=0 for all ranks). All grenade decisions go through the script's intelligent system:

• Self-damage prevention — No grenade throws within 300 units of self. Bots won't kill themselves.
• Conservative cooldowns — Shotguns: 20s. Skull & Knife: 25s. Skull: 35s. Bones/Crossed Bones: grenades disabled entirely.
• Gun ammo gating — Will not throw if primary weapon ammo is below 50%. Grenades are not a substitute for gun ammo.
• High crowd threshold — Requires 6+ nearby zombies (Shotguns) to 10+ (Bones) before considering a throw. No throwing at scattered targets.
• Round gating — No grenades before round 5. Early rounds use knife/gun economy exclusively.
• Cluster targeting — Grenades aimed at zombie cluster centroids within 300-600 unit range for maximum effectiveness.

Triple Line-of-Sight Verification

The single most important technical feature in Custom Bots. Every shot a bot fires passes through three independent line-of-sight checks. If any check fails, the bot stops firing immediately.

Additionally, at the moment of target acquisition (before any firing begins), a pathfinding validation check confirms the zombie is reachable and not trapped behind geometry. This eliminates the common AI behavior of fixating on zombies they can see through cracks but can't actually shoot.

Autonomy System

Autonomy is a per-rank value (0.15 for Bones, 0.95 for Shotguns) that controls how independently a bot behaves. Every decision has an autonomy threshold. When the bot's autonomy exceeds the threshold, it can make that decision on its own. Below the threshold, it defers to the leader or skips the action entirely.

This creates a natural spectrum: Bones bots are clingy followers that rarely act independently. Shotguns bots are almost entirely self-directed, only loosely tracking the leader's position while making their own plans.

Autonomy Thresholds

Leader Selection Intelligence

When a bot does follow a leader, it uses a scored selection system instead of just picking the nearest human. Each human player receives a leader score based on proximity and activity level. If a human has been stationary for 10+ seconds (velocity near zero), their leader score drops by 50%. This prevents bots from clustering around an AFK player while active players fight alone on the other side of the map.

Survivability System

Staying alive is a multi-layered system. Health, revive logic, flee behavior, and team defense all work together to keep bots in the fight.

Revive Logic

• Human Priority — Downed human players are always prioritized over downed bots. If two players are down, the human gets revived first.
• Danger Awareness — Before attempting a revive, bots count nearby zombies. With Juggernog, the threshold is 8 zombies. Without Juggernog, it drops to 4. If danger is too high, the bot fights its way to safety first.
• Clutch Revive — If a bot successfully revives someone while below 25% health, a special "CLUTCH REVIVE" splash displays on the HUD.
• Team Defense — Bots protect ALL teammates, not just their designated leader. If any teammate is in danger (multiple zombies closing in), nearby bots will engage those zombies.

Directional Flee

When the bot is overwhelmed (too many zombies within flee distance), it doesn't run to a random point. The flee system calculates the centroid of all nearby zombie positions, then moves in the opposite direction. It prefers paths that break line of sight with the zombie cluster, using nav nodes and cover positions.

Dynamic strafe distance scales with zombie count: fewer zombies = wider strafes (more evasive), many zombies = tighter strafes (more direct escape).

Elite Survivability (Shotguns Rank)

Shotguns-rank bots have several survival advantages: 700 HP (nearly 3x the base 250), faster health regeneration, and intelligent repositioning. When health drops below a critical threshold, elite bots break from their current action and seek a defensible position before re-engaging.

Early Game Flow

The first few rounds of a Zombies game have specific rhythms that experienced players follow. Custom Bots replicates this with a structured early game sequence that maximizes points and sets up the team for success.

Early Round Knife Strategy

In Zombies, knife kills in early rounds award 130 points vs. 60–70 for gun kills. Experienced players knife as much as possible in rounds 1–3 to build their point economy. Custom Bots replicates this strategy.

When knife_mode is active, the combat engine respects it: bots switch to their knife and engage zombies in melee range. The system tracks the number of bullets needed to soften a zombie for a one-hit knife kill based on the current round. On round 1, zombies die to a single knife. On round 2, one bullet + knife. On round 3, two bullets + knife.

On Origins, bots with the Iron Fist perk extend their knife rounds through round 8, since the upgraded melee damage makes knifing viable much longer.

Training AI

Training (zombie kiting) is the core high-round survival strategy in Zombies. You run in circles, let zombies pile up behind you into a tight horde, then turn and shoot them all at once. It's the most efficient way to clear rounds and it's what separates good players from great ones. Custom Bots does it autonomously.

Who Can Train

Training Process

Economy System

Points are the lifeblood of Zombies. Every purchase, from a 500-point door to a 5000-point Pack-a-Punch, is weighed against the bot's current financial situation, immediate needs, and round pressure. The decision engine handles all economy decisions simultaneously — perks, weapons, doors, ammo, box, and PaP all compete for the same pool of points.

Perk Priority System

Perks follow a base priority order but are dynamically adjusted based on the current situation:

Spending Priorities

• Emergency Ammo — Below 10% ammo = score 600 (urgent). Below 25% = score 300–500. Bots won't run dry if they can help it.
• Max Ammo Awareness — If a Max Ammo powerup is on the ground, ammo buy score drops to 0. Why spend points when free ammo is sitting right there?
• Weapon Upgrades — PaP is prioritized once the bot reaches pap_min_round with 5000+ points. The bot selects its best weapon to upgrade — not necessarily the one currently held.
• Door Investment — Doors are purchased when the bot has enough points AND the door leads somewhere useful (perk machine, Mystery Box, better training area).
• Point Reserve — Supportive personality bots keep a 1500-point buffer. They won't spend their last points on a non-essential purchase.

Weapon Scoring System

Every weapon in the game has a score that determines how desirable it is for bots. Scores are calculated from a combination of base weapon stats (damage, fire rate, magazine size), map-specific bonuses (some weapons are better on certain maps), and contextual modifiers (what the bot already has, how many points it has).

Scoring Factors

• Base Weapon Quality — Assault rifles and LMGs score higher than pistols and shotguns (with exceptions for wonder weapons and Pack-a-Punched weapons).
• Map Bonuses — Each map has a curated list of weapon preferences. The Sliquifier gets +80 on Die Rise. The Blundergat gets +80 on Mob. The Paralyzer gets +80 on Buried. See Map Weapon Preferences.
• Current Loadout — If the bot already has a strong primary, the urgency to acquire another weapon drops. If the bot only has a pistol at round 10+, weapon scores skyrocket.
• Cost Assessment — Expensive wallbuys are penalized when the bot is low on points. A 1500-point M14 might outscore a 3000-point Galil if the bot only has 3500 points.
• Launcher Blacklist — Launchers, RPGs, SMWAs, and War Machines receive -999. Self-damage weapons are too dangerous for AI.
• Ice Staff Reservation — On Origins, the Ice Staff is permanently reserved for human players. Bots will never pick up ice staff parts, crystals, or the completed weapon. This is hardcoded at every level of the weapon system.

Collectible & Buildable Pickup

Bots actively search for and collect buildable parts across all maps. They don't just stumble into parts — they route to known spawn locations and pick them up with purpose. After collecting enough parts, they navigate to the build table and craft the buildable.

Proactive Part Seeking

Bots don't wait to stumble across parts. They actively scan for buildable pieces using dynamic entity queries (getentarray) across 15+ targetname patterns, finding every part the game engine has spawned. The seeking system runs during early game to ensure parts are collected before they're needed.

On Origins, the proactive seeking system is particularly sophisticated. Bots navigate to all 6 generator locations using a 6-method search system (bot_find_generators()). They seek shovels with an 8-method search that includes trigger_use fallback detection. They patrol dig site locations and staff part spawns (excluding ice staff).

After collecting enough parts for a buildable, bots automatically navigate to the build table and craft the item. Shovel reservation ensures at least 1 shovel is always left for the human player.

Last Zombie Save & AFK Training

One of the most important features in any Zombies mod. When 1–2 zombies remain at the end of a round, every bot stops shooting. No exceptions. This is hardcoded, not scored — the decision engine cannot override it.

Bot Personality System

Every bot receives a randomly assigned personality at spawn that subtly influences all of its decisions. Personalities don't change fundamental capabilities (a Bones bot is still terrible regardless of personality), but they add variety and create situations where two Shotguns bots behave noticeably differently.

The dominant personality trait is displayed in the spawn notification when bots join the game (e.g., "BOT_Dempsey [Aggressive] joined"). All three traits exist on a spectrum — a bot is never purely one type. The dominant trait just has the strongest influence.

Bot Communication

Bots communicate through two channels: HUD notifications (visual splashes on screen) and chat messages. All callouts are throttled to 1 per bot per 3 seconds to prevent message spam.

Randomized Callout System

Instead of static strings, every callout uses a bot_random_callout() function that picks from an array of 4+ variants. This means the same situation produces different messages each time, making bots sound like distinct personalities.

Communication Categories

Round-Based Scaling

Bot stats aren't static. They improve as rounds progress using a carefully tuned logarithmic curve that provides fast improvement in early rounds and diminishing returns later. This mirrors how real players "warm up" and improve their play as a session goes on.

Logarithmic Curve

The primary scaling formula is 0.10 × log2(round), capped at 0.40 (reached around round 16). This curve is applied to:

• Aim Scatter — Reduces over time, making bots more accurate in later rounds.
• Headshot Chance — Increases, reflecting improved target selection.
• Reaction Time — Decreases, making bots faster to acquire targets.
• Burst Pause — Shorter pauses between bursts in later rounds.
• Revive Delay — Faster response to downed teammates.
• Crowd Flee Count — Higher tolerance before fleeing (bots get braver).
• Powerup Range — Wider search radius for powerup drops.
• Training Skill — Smoother, more reliable kiting patterns.

Elite Scaling (Round 40+)

After round 40, a secondary linear factor kicks in: (round - 40) × 0.005, capped at 0.15 (maxed at round 70). This is applied only to three stats to keep bots viable in ultra-high rounds without breaking early game balance:

• Headshot Chance — Higher headshot rate needed because zombie health scales exponentially.
• Crowd Flee Count — Higher tolerance because zombie spawns increase dramatically.
• Powerup Range — Wider search because powerups become critical for survival.

Downed Bot Behavior

When a bot goes down, it doesn't just lie there waiting. Downed bots have their own behavioral system that maximizes their chances of survival and contribution even while incapacitated.

Downed Actions

• Crawl Toward Teammates — Downed bots slowly crawl toward the nearest living teammate, reducing the distance the reviver needs to travel.
• Downed Combat — Using their pistol, downed bots scan for zombies within 500 units and engage them. This provides covering fire for teammates attempting the revive.
• Dynamic Headshots — Rank 3+ bots land headshots 70% of the time while downed, using the j_head bone tag for accurate aiming. This works correctly for crawlers (lower head), standing zombies, and tall bosses like the Panzer.
• Resource Lock Cleanup — The moment a bot goes down, all resource locks (Mystery Box, Pack-a-Punch, debris) are automatically cleared. This prevents permanent lockouts that could cripple the team.

Announcer System

The announcer provides dramatic HUD splashes at key moments throughout the game. These milestones celebrate progress and give the experience a polished, production-quality feel.

Round Milestones

Special Splashes

• BOTS DEPLOYED — Displayed when all bots have spawned and initialized successfully.
• Clutch Revive — Special splash when a bot revives someone while below 25% health. Celebrates the heroic play.
• Kill Milestones — Individual bot callouts at 50, 100, 200, and 500 kills. Shows which bots are carrying their weight.

HUD System

The HUD system provides real-time visual feedback about bot status, actions, and events. Every element is carefully positioned to avoid overlapping with the game's existing UI.

Element Positioning

Clean Lifecycle

All HUD elements follow a strict lifecycle: create, fade in, display, fade out, destroy. Elements are properly cleaned up on game end. The system handles edge cases like rapid succession events, simultaneous displays, and game-ending mid-animation.

Map-Specific Logic

Every BO2 Zombie map has unique mechanics that require specialized AI behavior. Custom Bots has dedicated logic for all 6 maps.

Map Weapon Preferences

Each map has a curated weapon preference list that adds bonus scores to certain weapons. These bonuses stack with the base weapon quality score to guide bots toward the best weapons available on each map. Higher bonus = higher priority.

Easter Egg Support

Custom Bots provides step-by-step Easter Egg assistance on all 6 BO2 Zombie maps. Toggled via bo2_zm_bots_ee (enabled by default). The core philosophy is simple:

Health Gate Safety: If a bot drops below 30% health during an active Easter Egg objective, the EE goal pauses for 3 seconds. The combat and flee systems take over until the bot stabilizes, then the EE goal resumes. This prevents bots from standing on an EE position while being overwhelmed by zombies.

Hazard Detection

Each map has environmental hazards that damage or slow players. The hazard detection system identifies these zones and routes bots around them. Hazard awareness scales with rank — Shotguns bots always avoid every hazard, while Bones bots stumble through them regularly.

Hazard Avoidance by Rank

• Shotguns (100%) — Perfect avoidance. Never touches a hazard.
• Skull & Knife (85%) — Occasional misstep in tight areas.
• Skull (60%) — Usually avoids hazards, sometimes walks through mud.
• Crossed Bones (40%) — Regularly takes unnecessary hazard damage.
• Bones (20%) — Basically ignores hazards. Walks straight through lava.

Smart Navigation & Positioning

Bots don't just pathfind to destinations. They position themselves intelligently relative to teammates, zombies, and map geometry.

Spread-Out System

When not actively pursuing a goal, bots maintain distance from each other using a cover angle system. Each bot faces a different direction (distributed evenly around 360°) to maximize map awareness. The spread radius scales with player count: more players = wider spread.

Smart Player Dodge

When a human player is looking at a bot AND moving toward it (calculated via dot product of player's forward vector and direction to bot, threshold > 0.7), the bot steps perpendicular to the player's movement direction. Instead of randomly teleporting away, the bot naturally sidesteps like a real person would when blocking a doorway.

Window Defense

During early rounds, bots claim windows using a 1200-unit search range and defend them against boarding zombies. A dynamic round cap prevents bots from overstaying at windows when the round gets too chaotic. Window defense is skipped entirely by elite bots (rank 3+) after round 3.

Dynamic Entity Discovery

Nothing is hardcoded to specific map coordinates. Bots use getentarray() to dynamically find every point of interest at runtime — perk machines, doors, debris, wallbuys, Mystery Box locations, Pack-a-Punch, generators, buildable parts, traps, and Easter Egg entities. The system queries 90+ entity patterns across multiple targetname fallbacks to ensure compatibility with all map variants and custom configurations. Training patrol routes are the only exception — those are hand-designed navigation circuits that define safe running paths.

Stuck Detection & Recovery

Rank-scaled stuck detection monitors bot movement. If a bot's position hasn't changed significantly within the timeout window, a full recovery sequence initiates: all goals are cleared (61 labels swept), the bot teleports to a safe position, and the decision engine restarts from scratch.

Safety & Stability

Custom Bots is engineered for crash-free long sessions. When you're going for round 100+, stability isn't optional — it's the most important feature. Every system has redundant safety guards and graceful failure modes.

Loop Safety

• 76 endon guards — Every threaded function includes endon guards for death, disconnect, and game_ended events. If the game state changes, all bot threads terminate cleanly instead of erroring out.
• 637 IsDefined checks — Before accessing any entity, variable, or reference, the code verifies it still exists. Entities can be destroyed by the game engine at any time — every access is guarded.
• 68 isAlive checks — Dead bots don't try to act. Every action entry point verifies the bot is alive before proceeding.
• 200-tick training abort — Training circuits have a maximum iteration counter. If a circuit runs for 200 ticks without completing, it aborts to prevent infinite loops.

Resource Management

• Resource Locks — Mystery Box, Pack-a-Punch, generators, and doors each have a lock system preventing multiple bots from accessing the same resource simultaneously. All locks auto-clear on disconnect, laststand, or game end.
• 61-Label Goal Sweep — On every stuck reset and respawn, all 61 possible goal labels are cleared from the bot. No stale goals survive a recovery cycle.
• Ghost Player Kick — Every 10 seconds, a sweep checks for invalid player references and removes them. Prevents crashes from disconnected clients.

Combat Safety

• Triple LOS — Every shot is verified against three independent line-of-sight checks. Zero wall-shooting.
• 3-Frame Stale Clearing — If a target fails LOS for 3 consecutive frames, it's dropped. No fixating on invisible targets.
• No Scatter <150u — At close range, aim scatter is disabled entirely. Direct aim only.
• No Fallback Shooting — If the final aim point fails LOS, the bot stops shooting. No hopeful wall-spraying.
• takeweapon() Only — Weapon swaps always use takeweapon(), never takeallweapons(). This preserves the bot's knife, grenades, and tactical equipment.

Anti-Crash Engineering

The T6 GSC engine has many undocumented limitations and crash triggers. Custom Bots handles all of them.

Known T6 GSC Pitfalls

Functions That Don't Exist in T6 GSC

Many common scripting functions from other CoD titles don't exist in the T6 engine. Using them causes silent failures or crashes:

• exec(), setname(), setclantag() — Not available in T6
• pressusebutton(), pressuse(), pressfrag() — Not available in T6
• pressmelee() with parameters — Exists but parameters are ignored
• takeallweapons() — Exists but strips everything including knife. Custom Bots uses takeweapon() instead to preserve loadout.

File Architecture

The entire codebase lives in a single file with 44 clearly delineated sections using Unicode box-drawing borders. Each section has a standardized header format with its number, name, and a brief description.

Border Formatting

Every section uses Unicode box-drawing characters for visual clarity. Three border widths are used consistently throughout:

• Section Headers — 76 ═ characters (81 total including ║ and spacing)
• Medium Functions — 74 ═ characters (79 total)
• Small Functions — 71 ═ characters (76 total)

Technical Deep Dive

For modders and developers who want to understand how the code works under the hood.

GSC Engine Details

GSC (Game Script Code) is Treyarch's proprietary scripting language for Call of Duty. It runs server-side, is single-threaded with cooperative multitasking (using wait statements), and has access to the game's entity system, animation system, and AI navigation mesh.

Key technical constraints:

• No arrays of structs — arrays can only hold primitives or entity references
• No string concatenation at runtime without + operator
• No try/catch — every error is a server crash
• No modules or imports from custom files (only game-provided includes)
• No dynamic function calls or reflection
• All bot commands are fire-and-forget — no confirmation of execution

Trigger Interaction System

T6 uses a complex trigger hierarchy for interactive elements. bot_trigger_entity() implements a 4-path fallback system to interact with any trigger type:

1. unitrigger_stub → use_trigger (primary path)
2. trigger property (secondary path)
3. trigger_stub property (tertiary path)
4. Direct entity notify (last resort)

This layered approach ensures bots can interact with doors, perk machines, buildable tables, and other interactive elements across all maps, regardless of how each map's triggers are structured.

Entity Search Methods

Finding entities (parts, weapons, triggers) in T6 requires multiple approaches because different maps use different naming conventions. The collectible system uses a 10-target entity name search. The shovel finder uses an 8-method search. The generator finder uses a 6-method search. Each method tries progressively broader searches until the target is found.

Navigation & Pathfinding

T6 provides a navigation mesh that bots can query for pathfinding. Custom Bots uses nav nodes for training circuit construction, hazard checking (midpoint analysis between waypoints), and safe position finding. When the nav mesh fails (common in complex geometry), the stuck detection system kicks in and teleports the bot to a known safe position.

Frequently Asked Questions

Addon Development Guide

A complete template file (custom_bots_addon_template.gsc) is included for developers who want to add custom behaviors without modifying the main script. The addon system hooks into spawned bots automatically and provides a clean interface for extending behavior.

What You Can Do

• Custom State Logic — Add new behavioral states that trigger under specific conditions
• Custom Callouts — Add new chat messages and HUD notifications
• Movement Overrides — Modify bot movement in specific situations or map areas
• Targeting Rules — Add custom target priorities or exclusions
• Weapon Preferences — Override weapon scoring for specific scenarios
• Map-Specific Logic — Add behaviors for custom map areas or mechanics
• Round-Based Events — Trigger actions at specific round numbers

Setup

Credits

Created by Astroolean

11,066 lines of autonomous zombie-killing intelligence, built from the ground up for the Plutonium T6 community.

Inspired by osmnbtrclk/bo2_zm_bots. Completely independent rewrite with different architecture, different AI systems, and different features. Credit where due for the original concept and inspiration.

Version 5.0.0 — 2026 Edition