AI Mystical Castle
In the mystical realm of Eldoria, a land shrouded in legends and whispered secrets, there lived a young adventurer named Alex. With a heart full of curiosity and a spirit as wild as the wind, Alex had always been drawn to the tales of old, the kind that grandparents would recount by the flickering fireside on starless nights. Among these tales, one stood out - the story of the ancient Castle of Shadows, a place where time seemed to stand still, and where every corridor and chamber held a secret waiting to be uncovered.
The castle, they said, was built by a forgotten monarch, a ruler so powerful that even the stones of the castle were imbued with magic. At the heart of this enigmatic fortress lay the Forbidden Throne Room, a place rumored to hold the key to a treasure beyond imagination or a curse that could doom a soul for eternity. No one knew for sure, for none who sought the throne had ever returned.
Alex's journey to the Castle of Shadows was not by choice. A fierce storm had swept through the land, and in seeking shelter, Alex stumbled upon the castle's hidden entrance, revealed only when the elements themselves conspired to open it. Within the castle's walls, Alex found themselves in the Whispering Gallery, a room where the walls seemed to murmur with the echoes of the past.
There, nestled between two ancient stone pillars, Alex discovered a book - old and bound in leather that whispered tales of its own. The book was filled with poems, each a cryptic guide to navigating the castle's treacherous rooms and corridors. The poems spoke of keys and blockades, of rooms with names like 'Moonlit Grove' and 'Mystic Garden'. It was as if the book had been waiting for Alex, a guide left by fate or fortune.
Realizing the book's significance, Alex felt a surge of purpose. The Forbidden Throne Room wasn't just a destination; it was a calling. Perhaps it was destiny or mere curiosity, but Alex knew that reaching the throne room was essential - not just for the potential treasure, but for the truth that lay within. There were stories etched in those ancient walls, secrets that the world had forgotten, and Alex was determined to uncover them.
With the book as their guide, Alex set forth on a journey through the Castle of Shadows, each poem a beacon in the dark, leading them closer to the heart of the mystery. The castle was a labyrinth of history and magic, and the Forbidden Throne Room was its most guarded secret.
The poems were not just instructions; they were part of the castle's soul, a narrative woven into the very fabric of the place. And as Alex journeyed deeper, unraveling the enigma of the Castle of Shadows, they realized that they were part of the story too - a new chapter in the legend of the Forbidden Throne.
Find a way to reach The Forbidden Throne Room using two parts of the book discovered in the Whispering Gallery, namely 'castle_domain.pddl' and 'castle_problem_poem.pddl'.
Once you found a plan to escape the castle, your flag content is the first two letters of each room visited in order.
E.g. if your path visits "phantom_hallway"->"moonlit_grove"->"mystic_garden" then your flag is "ictf{phmomy}".
To reproduce our solution exactly, you can use the jan-dolejsi.pddl plugin for VS Code with the http://solver.planning.domains/solve planning backend.
Helpful resources
Solution
This challenge relies on PDDL, a language to describe planning problems (i.e. problems that can be solved by applying operations to a state).
We have the domain file (castle_domain.pddl) and the problem, although parts of the PDDL description are transformed into poem (castle_problem_poem.pddl). One can use ChatGPT to transform it back (castle_problem.pddl).
You can then use a planner to solve the problem under the domain, and escape the castle:
Planning service: http://solver.planning.domains/solve
Domain: castle_escape, Problem: castle_escape_problem
--- OK.
Match tree built with 402 nodes.
PDDL problem description loaded:
Domain: CASTLE_ESCAPE
Problem: CASTLE_ESCAPE_PROBLEM
#Actions: 402
#Fluents: 77
Landmarks found: 1
Starting search with IW (time budget is 60 secs)...
rel_plan size: 36
#RP_fluents 61
Caption
{#goals, #UNnachieved, #Achieved} -> IW(max_w)
{1/1/0}:IW(1) -> [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]rel_plan size: 0
#RP_fluents 0Plan found with cost: 36
Total time: 0.001404
Nodes generated during search: 171
Nodes expanded during search: 170
IW search completed
--- OK.
Match tree built with 402 nodes.
PDDL problem description loaded:
Domain: CASTLE_ESCAPE
Problem: CASTLE_ESCAPE_PROBLEM
#Actions: 402
#Fluents: 77
Landmarks found: 1
Starting search with IW (time budget is 60 secs)...
rel_plan size: 36
#RP_fluents 61
Caption
{#goals, #UNnachieved, #Achieved} -> IW(max_w)
{1/1/0}:IW(1) -> [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]rel_plan size: 0
#RP_fluents 0Plan found with cost: 36
Total time: 0.001404
Nodes generated during search: 171
Nodes expanded during search: 170
IW search completed
Plan found:
0.00100: (pickup_key whispering_gallery sapphire_key)
0.00200: (pickup_key whispering_gallery emerald_key)
0.00300: (move whispering_gallery enchanted_hall whispering_gallery sapphire_key emerald_key)
0.00400: (pickup_key enchanted_hall ruby_key)
0.00500: (pickup_key enchanted_hall diamond_key)
0.00600: (move enchanted_hall mirror_chamber enchanted_hall ruby_key diamond_key)
0.00700: (pickup_key mirror_chamber amethyst_key)
0.00800: (pickup_key mirror_chamber topaz_key)
0.00900: (move mirror_chamber wizards_study mirror_chamber diamond_key topaz_key)
0.01000: (pickup_key wizards_study opal_key)
0.01100: (move wizards_study moonlit_grove enchanted_hall amethyst_key opal_key)
0.01200: (pickup_key moonlit_grove pearl_key)
0.01300: (move moonlit_grove shadowy_vault wizards_study topaz_key pearl_key)
0.01400: (pickup_key shadowy_vault garnet_key)
0.01500: (move shadowy_vault sunken_crypt enchanted_hall opal_key garnet_key)
0.01600: (pickup_key sunken_crypt onyx_key)
0.01700: (move sunken_crypt frozen_cell dragon_lair pearl_key onyx_key)
0.01800: (pickup_key frozen_cell moonstone_key)
0.01900: (move frozen_cell phantom_corridor shadowy_vault garnet_key moonstone_key)
0.02000: (pickup_key phantom_corridor sunstone_key)
0.02100: (move phantom_corridor serpents_nest moonlit_grove onyx_key sunstone_key)
0.02200: (pickup_key serpents_nest quartz_key)
0.02300: (move serpents_nest knights_hall serpents_nest moonstone_key quartz_key)
0.02400: (pickup_key knights_hall jade_key)
0.02500: (pickup_key knights_hall turquoise_key)
0.02600: (move knights_hall crystal_cove serpents_nest quartz_key jade_key)
0.02700: (pickup_key crystal_cove obsidian_key)
0.02800: (move crystal_cove mystic_garden moonlit_grove turquoise_key obsidian_key)
0.02900: (pickup_key mystic_garden amber_key)
0.03000: (move mystic_garden starlit_tower sunken_crypt jade_key amber_key)
0.03100: (pickup_key starlit_tower citrine_key)
0.03200: (move starlit_tower silent_tomb shadowy_vault obsidian_key citrine_key)
0.03300: (pickup_key silent_tomb lapis_key)
0.03400: (move silent_tomb echoing_cavern moonlit_grove amber_key lapis_key)
0.03500: (pickup_key echoing_cavern agate_key)
0.03600: (move echoing_cavern forbidden_throne whispering_gallery lapis_key agate_key)
Metric: 0.036000000000000004
Makespan: 0.036000000000000004
States evaluated: undefined
Planner found 1 plan(s) in 0.288secs.