There are two machines in the Tiamat Operations Center that will take players to the Nightmare World. Nightmare Entrance Machine A and Nightmare Entrance Machine B will take players to Nightmare World: Horror and Nightmare World: Terror, respectively. There is a base entrance limit of 6 times per day (increased by weekend bonus and VIP bonus) and 5 stamina will be consumed. Each time the player enters the dungeons, a random stage from a preset selection will be chosen.
Unique to the Nightmare World dungeons are the various bonuses a player may receive for completing a run. While the player is progressing through the stage, a small list of up to 4 objectives will be located in the lower right corner. Achieving each objective will reward the player with one item at the completion of the stage. Additionally, players will receive bonus items each time they complete three dungeons. The three dungeon completion reward is tracked separately for each machine. There is also rewards for total completions of the dungeons for 10, 30, 50, and 100 runs. To receive the rewards, the player must turn in the corresponding achievement.
- Every 3 runs: Four of the following - Golden Malek Statue (Worth 100,000 credits), an old key fragment ( 낡은 열쇠 자루 ), one random chip box, four random chip boxes of the same type, box containing 1~330 of the 300k creds item
- 10 total runs: Lucky-No-Fail Box (Contains one of 5 items listed)
- 30 total runs: Di-Oxi Cleaner ( 다이옥시크리너 )
- 50 total runs: A box containing a random accessory
- 100 total runs: A box containing a random accessory
During the run, an image of Tiamat will occasionally appear on the player's screen. At this point in time, one of three attacks will be cast on the players.
- Single Pillar: A red circle will appear below every player. After a delay, the red circle will cause a cylindrical explosion dealing heavy damage. If players are near each other, it is possible to get hit by multiple pillars and potentially die.
- Four pillars: One player will have four red circles appear below them in the cardinal directions. The player will have to dodge each pillar in the order that the circles appeared. It is recommended that this player move away from their party members. If the player is unable to move out of the way or perfect evade the pillars, he/she will have to use force cancel to prevent death.
- Death Mark: One player will have a mark appear above their head. There will be a small cylindrical area around the player as well. After a delay, any players that are not within this cylindrical area will be kill. It is recommended that the player who has the death mark stand still, preferably away from monsters, while the other party members stand in the same spot as the death marked player or use skills with invincibility to avoid the attack.
If the players successfully clear the block before the attack casts and do not move to the next block, the attacks will cause no damage.
Possible Mission Objectives
The following is a list of possible bonus objectives the player may have inside the dungeons.
- Complete the dungeon within 10 minutes
- Complete the dungeon with at least a S rank
- Complete the dungeon with at least a SS rank
- 6 of something
- 1 of something
- 1 of another thing
The following is a list of possible rewards for completing the bonus objectives.
- Amplified Dimensional Essence ( 증폭된 차원의 정수 )
- Sealed Eyes of the Queen ( 봉인된 여왕의 눈동자 )
- Demon's Goblet ( 마왕의 잔 )
- Common Phase Fiber ( 흔한 위상 섬유 )