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 North America: Zombie Mode 3
- CF Vietnam: AI Mode 3
- CF Russia: Zombie 3
- CF Japan: Undead 3
- CF Brazil: Zombie 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.
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).
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 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.
Deploys a sentry that fires on sight.
Mine that explode nearby zombies.
It slows down / damages zombies.
Health Flag that heals the team.
It flies around and shoots enemies.
Increased maximum health points.
Increased maximum armour points.
Increase damage against Human targets
Increase damage against Bio targets
Increased damages against Mechs
Decreased revival timer.
More damage against common enemies.
Increase chances to stun Longbill
Able to score Critical hit against Human targets
Able to score Critical hit against Bio targets
Able to score Critical hit against Mechs
- Main article: Skill upgrades