A map of Geno Dome, a dungeon in 2300 AD, in Chrono Trigger.

Geno Dome, 2300 AD - Enemies
  • Deverminator EX - 1,024 HP - Weak to Light - Drop Shield Sphere - Charm Elixir
  • Laser Guard - 400 HP - Weak to Light - Charm Hi-Potion
  • Version 4.0 - 1,024 HP - Weak to Light - Drop Barrier Sphere - Charm Elixir

  • Once the Epoch has wings you'll unlock a string of side quests, and as far as combat strength goes the Geno Dome of 2300 AD should be your first stop. Put Robo in your party and fly to the Geno Dome. You’ll find it to the southeast of Proto Dome, on a small, remote island. Light attacks are very useful in this place, so consider bringing along Crono and / or Magus, as well.

    Once inside, assuming you have Robo leading your party, you can use the nearby computer console to open a door to a long conveyor belt. The conveyor subjects you to a series of battles against robots, namely Deverminator EXes and Version 4.0s. These things are weak against Light attacks, and Lightning II / Luminaire should wreck crowds of them with little problem. This conveyor belt is a fantastic place to grind levels and TP quickly for the rest of the game, though once you beat this area it closes down permanently.

    The party explores the Geno Dome, an optional dungeon in Chrono Trigger.

    Reach the end of the conveyor in one piece and you'll find the first floor of Geno Dome. Head east in the starting corridor. There’s a chute in the far right corner which you can use to return to the entrance. Use it if necessary; otherwise, head north and into the first door you see. There are three Version 4.0s inside that will attack if you try to take the Elixir or the Lapis from the chests on the right side of the room.

    Return to the corridor and hop on the conveyor belt to your left. Run north, hop off on your left, and hit the switch beside the door. This will open a little pod in the wall, one that you can enter. It’s no use just yet, but you’ll want it open soon.

    Return to the entrance of this section of Geno Dome. Take out the Deverminators guarding the far-west corridor, then go back east one hallway and head north to fight some Version 4.0s. Check their room for a chest containing a Hi-Potion, as well as a computer with info about the dome, then go through the door on the left. There are four Laser Guards straight ahead. Again, Light attacks will rip them apart. Beyond the Laser Guards are three switches, and if you hit the left and right switches you'll open a wall pod in the previous room, beside a locked door. We'll come back to this.

    Robo builds up an electrical charge in the Geno Dome, an optional dungeon in Chrono Trigger.

    Head back to the room where you just mauled some Version 4.0s. If you open the wall pod beside the computer and position Robo inside he will build up, and carry, an electrical charge. You can use this charge to pop open locked doors by getting Robo into wall pods before the electricity dissipates. Using this charge you can open three doors:
    • A door near the entrance, inside which you’ll find a Hi-Potion and 50,000 G
    • The door beside the switch-locked wall pod in the northwest, which will allow you to grab a Poyozo Doll
    • The door beyond the conveyor belt in the north - we'll work on this in a moment
    The electrical charge doesn't last forever, so don't waste time.

    Head back to the entrance and go through the door near the eastern chute that you skipped earlier. It leads to an elevator, and at the top you’ll find a save point. Beside the save point is a door. Go through and down the northern corridor - keep your eyes open for a Strength Capsule on your right, near the south entrance - to find another door. This one is protected by two Version 4.0s and two Laser Guards. Past the door is an elevator leading back to the previous level.

    Two Laser Guards wait to the south. Take ‘em out, then go back north and walk west of the door to the elevator, through the wall decorated with a green arrow. Beyond the wall is a switch that changes the direction of the conveyor belt to the south. Head back to the door and go south to reach the conveyor belt.

    The party opens a door in the Geno Dome, an optional dungeon in Chrono Trigger.

    Run down the conveyor and back to the pod that supplies an electric charge. Hop inside to charge Robo, then immediately rush counterclockwise around the area, back up the conveyor belt, and into the wall pod beside the door on the left side of the conveyor. You should have just enough time to open the door. Beyond are two chests containing a Turbo Ether and a Hi-Ether. There's also a robot here that's curiously sedate...

    ... or at least it is until you touch it, which prompts the robot to follow the team around. Lead the robot south and to the southwest corner of the floor. Be patient, as the robot is slow, gets caught on the geography, and will flee if it runs into any enemies along the way. In the southwest you’ll find a second robot, guarding another Poyozo Doll. The two robots lock into place against each other, allowing you to slip by and grab the doll. Also here is a chest containing a Vigilant’s Hat.

    Take the elevator by the escape to the second floor. It'll ferry you to to the room with the save point. Use a Shelter, save, take out the Laser Guards nearby, check the chest near the save point for a Lapis, and make your way west. A boss is waiting if you collected both Poyozo Dolls.

    Robo takes on Atropos XR, his former paramour, while plunging through Geno Dome in 2300 AD

    Atropos XR

    HP: 6,000

    Ouch. Emotional battle. Robo will have to face Atropos XR alone, but it’s not that difficult a fight. Robo's pink doppelganger uses many of the same moves, though her versions do a lot less damage. They include:
    • Rocket Punch
    • Laser Spin
    • Cure Beam
    • Robo Tackle, which cuts Robo's HP in half
    • Rapid-fire Fist
    • Proximity Bomb
    Use Cure Beam to keep Robo strong, then unleash Robo's strongest Techs to chip away at Atropos XR’s HP. Robo Tackle is ideal, as it won’t eat through Robo's MP too quickly, though if he has either a Silver or Golden Stud equipped you can use Rapid-fire Fist to really rip Atropos XR apart.

    Besting Atropos XR bestows Robo with Atropos's Ribbon, permanently raising Robo’s Speed by three and his Magic Defense by 10. 

    A wall switch in the Geno Dome, an optional dungeon in Chrono Trigger. You need to get a bit of a running start to hit it.

    Behind this battlefield is a room with some items, protected by laser fields. There's a switch, but it's just out of reach. Walk south of the switch, the run at it and press the confirm button about halfway there. If you time this correctly Robo will leap into the air and hit the switch, deactivating the laser field. On the other side you'll find a chest containing a Megaelixir, as well as a Magic Capsule, sitting on the ground in the bottom-right corner.

    Run back to the save point already to heal up and save. Head west from here and down the stairs before crossing the large, guarded bridge. Along a nearby catwalk you’ll find a chest containing 15,000 G, and in a rear room you'll discover... something gruesome. Check through the right door to find a Hi-Ether.

    Return to the main path and head north. Destroy the Laser Guards on the path... a lot of Laser Guards... then place the Poyozo Dolls you found earlier on the two green lights to the right and left of the large security door in the north. This opens the door to the final battle of Geno Dome.

    Robo leads his comrades in battling Mother Brain, one of the great powers of 2300 AD

    Mother Brain

    • 5,000 (Mother Brain)
    • 1 (Displays)
    • Blue Plate (Mother Brain)
    • Elixir (Displays)
    The leader of 2300 AD's robots, Mother Brain is a tricky combatant. She uses the following attacks:
    • A beam attack against a single target
    • A beam attack against your whole party
    • A stronger beam attack against the whole party (only when Displays are gone)
    • Reprogram, which Confuses a single target
    • Memory Reset, which can Lock one or more of your party members
    Mother Brain begins the fight as a relatively tame opponent, using some simple attacks and status ailments to pester the party. Little trouble, really - except that the Displays surrounding her, three in all, constantly provide Mother Brain with healing energy. Unless your damage output is ridiculously high, the Displays undo all your work. Unfortunately, destroying them puts Mother Brain on the rampage, increasing her attack power and unlocking some new moves. 

    The solution? Don’t destroy all of the displays. Take out two of the three, leaving one untouched. This Display will continue to heal Mother Brain, but she won’t be able to keep up with your damage output. That done, pummel her with single-hitting Dual and Triple Techs until she falls. As long as you focus solely on Mother Brain from this point on you should win the battle without too much trouble. If you find you can't outpace the Display's healing energy then you'll have to take it out - just make sure one person is always ready to heal the party.

    The party defeats the Mother Brain and deactivates the Geno Dome, an optional dungeon in Chrono Trigger.

    Beating Mother Brain earns you the Teraton Arm and the Crisis Arm, both weapons for Robo. It also locks the Geno Dome for good, bringing this side quest to an end.