Trial Challenge Mode (AI Mode 3) is the third installment of PVE mode in CrossFire. It goes back to the classic formula which pits soldiers against the zombies plus a boss, but incorporates some new elements inspired from Defense Mode and Wave Mode.


  • CF China: Trial Challenge Mode
  • CF West: Zombie Mode 3
  • CF Vietnam: AI Mode 3
  • CF Russia: Zombie 3
  • CF Japan: Undead 3
  • CF Brazil: Zombie Mode 3
  • CF Español: Zombie Mode 3
  • CF Philippines: Zombie Apocalypse 3
  • CF Indonesia: Zombie Land Mode 3


A maximum of 5 players can enter a room, but only one required to start the game. Soldiers must choose their Class before starting; five different classes provides soldiers with different tools to use against the Zombies. The default option is always Drone.

This time, there are 5 difficulty levels to choose from (Similar to AI Bot Mode), although all of them will have different numbers of rounds. If started with only one players, the difficulty will be dynamically balanced based on players' AI-level, starting from Easy to Very Hard (and if a player gets disconnected, it will revert back to lower difficulty).

AI3 Easy AI3 Normal AI3 Hard AI3 VeryHard AI3 Nightmare

Soldiers once again are tasked to eliminate the zombies in an enclosed area and defeat the boss guarding it to win. However, Revive Token are no longer a mandatory requirement to continue playing after losing all default lives. Instead, players can wait for 40 seconds (or lower using specific skills) and they will respawn, but if all Soldiers are killed and no one revives within 10 seconds, the match will be over.

Also players can now quick-revive teammates by pressing F5 to F9 (based on teammates' position; the button will appear over dead teammates' bodies as hints), thus eliminating the need to walk over to your teammates (The H command is now exclusive to self-revive, and Macro Chat is not possible in this mode).

Each soldier can now deploy tools to help to fight off the zombies, ranging from Sentry Gun, Drone, Claymore, etc. Unlike in Defense Mode, these tools are indestructible and won't require repairing - instead, they will last for a predetermined time before vanishing (Applied to Claymore as well, in case it's placed at places that's unreachable by zombies by mistake), at which point soldiers will have to wait till the cool down timer expires in order to deploy the tools again.

The zombies are now broken into three category: Bio, Mechanical, Human, indicated by Cyan, Green and Red color respectively. Players can tell the enemy type by the damage indicator that shows up whenever they hit the zombies (Colors will determine the enemy types as stated earlier). Bosses still have their large Lifebar at the top of the screen, but in higher difficulty, they will have multi-lifebar, indicated by the colors and the number next to it.

The classic Reward Crates return, although now it only gives one prize upon opening (Two with Boss crates) Crates are awarded after beating a Boss based on damage inflicted during the previous round(s) by players. There's a special Bonus Crate which's used in Hell Tower to award players with random prize should they succeed in the Bonus Round. New to the system is the Puzzle Piece that players can collect to craft into weapon (similar to the Combination Item System).

After each match completed, players will receive in-mode EXPs and climb up ranks similar to Wave Mode. Leveling up also award players with Skill Points that they can use to upgrade their abilities and skills to make the game easier.

  • This is the first Zombie Mode that allow players to play alone, probably owing to the fact that it's difficult to get 5 players into the room to start with. It's also the first mode that give players free revival based on a timer.
    • Both of these settings have been adapted into classic ZM in CF Brazil.
  • With the release of new Loading Screen in CF Vietnam, the difficulty tags are now shared with all ZM modes. This creates inconsistency because the Very Easy, Easy and Medium tag are used for Easy, Medium and Hard difficulty respectively on ZM/ZM2. Text strings are still correct however.
  • In CF Philippines, this mode has a glitch when choosing special weapon type before entering the game and during the gameplay players health can't recover when using HypoMed-S or HypoMed-L the counter always 0 even players they already have. Only Revive Token can be use upon dying when losing basic lives. The special weapon type glitch is now fixed after certain patches.


AI3 Sentry-Gun
Sentry Gun:
Deploys a sentry gun that shoots zombies on sight.
AI3 Claymore
Claymore Mine:
A proximity mine that explodes upon contact with zombies.
AI3 Plasma-Shocker
Plasma Shocker:
It slows down / damages zombies.
AI3 Recovery-HP-Base
Health Recovery:
Health Flag that heals the team.
AI3 Drone
UAV Drone:
It flies around and shoots enemies.
AI3 Drone-Reinforce
UAV Drone (Reinforcement):
Same as Drone but with double firepower.
AI3 Grenade-Turret
Grenade Turret:
Shoots grenades and deal damage plus splash explosion.
AI3 Spike-Missile
Spike Missile:
Shoots a wave of missiles and deal damage.
AI3 Drone-Gold
UAV Drone (Gold):
It flies around and shoots enemies.
AI3 Recovery-HP-Base Gold
Health Recovery (Gold):
Health Flag that heals the team.

AI3 Skill HP
Health Points:
Increased maximum health points.
AI3 Skill AC
Armor Class:
Increased maximum armour points.
AI3 Skill Human-Damage
Human Damage:
Increase damage against Human targets
AI3 Skill Bio-Damage
Increase damage against Bio targets
AI3 Skill Mechanical-Damage
Mechanical Damage:
Increased damages against Mechs
AI3 Skill Revival
Decreased revival timer.
AI3 Skill General-Damage
General Damage:
More damage against common enemies.
AI3 Skill IrresForce
Irresistible Force:
Increase damage against bosses when they are stunned
AI3 Skill HumanCrit
Human Damage (Critical):
Able to score Critical hit against Human targets
AI3 Skill BioCrit
Bio-Damage (Critical):
Able to score Critical hit against Bio targets
AI3 Skill MechCrit
Mechanical Damage (Critical):
Able to score Critical hit against Mechs

Skill upgrades

Main article: Skill upgrades
Community content is available under CC-BY-SA unless otherwise noted.