COMP3702 Artificial Intelligence (Semester 2, 2021) The DragonGame AI Environment This document provides a high-level description of the DragonGame environment. The support code can be found at: https://gitlab.com/3702-2021/a1-support. Background “Untitled Dragon Game”1 or simply DragonGame, is a 2.5D Platformer game in which the player must collect all of the gems in each level and reach the exit portal, making use of a jump-and-glide movement mechanic, and avoiding landing on lava tiles. DragonGame is inspired by the “Spyro the Dragon” game series from the original PlayStation. To optimally solve a level, your AI agent must find a sequence of actions which collects all gems and reaches the exit while incurring the minimum possible action cost. Levels in DragonGame are composed of a 2D grid of tiles, where each tile contains a character representing the tile type. An example game level is shown below: XXXXXXXXXXXXXXXXXXXX XX XXXXXX X G XXXX XXX=X XX X = G X X = XX= X X = G = X X=XXXXXX = X X= X = G X X= X = XXXX X= =X = XX X X=XX G =XX = EX X=PXXX XXXXXXX =X XXXXXX**XXXXXXX**XXX Figure 1: Example game level of DragonGame 1This full game title was inspired by Untitled Goose Game, an Indie game developed by some Australians in 2019 1 COMP3702 The DragonGame AI Environment Game state representation Each game state is represented as a character array, representing the tile types and their position on the board. In the visualizer and interactive sessions, the tile descriptions are triples of characters, whereas in the input file these are single characters. Levels can contain the tile types described in Table 1. Table 1: Table of tiles in DragonGame, their corresponding symbol and effect Tile Symbol in Input File Symbol in Visualiser Effect Solid ‘X’ ‘XXX’ The player cannot move into a Solid tile. Walk and jump actions are valid when the player is directly above a Solid tile. Ladder ‘=’ ‘===’ The player can move through Ladder tiles. Walk, jump, glide and drop actions are all valid when the player is directly above a Ladder tile. Air ‘ ’ ‘ ’ The player can move through Air tiles. Glide and drop actions are all valid when the player is directly above an Air tile. Lava ‘*’ ‘***’ The player cannot move into a Lava tile. Moving into a tile directly above a Lava tile results in Game Over. Gem ‘G’ ‘ G ’ Gems are collected (disappearing from view) when the player moves onto the tile containing the gem. The player must collect all gems in order to complete the level. Gem tiles behave as ‘Air’ tiles, and become ‘Air’ tiles after the gem is collected. Exit ‘E’ ‘ E ’ Moving to the Exit tile after collecting all gems completes the level. Exit tiles behave as ‘Air’ tiles. Player ‘P’ ‘ P ’ The player starts at the position in the input file where this tile occurs. The player always starts on an ‘Air’ tile. In the visualiser, the type of tile behind the player is shown in place of the spaces. Page 2 COMP3702 The DragonGame AI Environment Actions At each time step, the player is prompted to select an action. Each action has an associated cost, representing the amount of energy used by performing that action. Each action also has requirements which must be satisfied by the current state in order for the action to be valid. The set of available actions, costs and requirements for each action are shown in Table 2. Table 2: Table of available actions, costs and requirements Action Symbol Cost Description Validity Requirements Walk Left wl 1.0 Move left by 1 position Walk Right wr 1.0 Move right by 1 position Jump j 2.0 Move up by 1 po- sition. Current player must be above a Solid or Ladder tile, and new player position must not be a Solid tile. Glide Left 1 gl1 0.7 Move left by 1 and down by 1. Glide Left 2 gl2 1.0 Move left by 2 and down by 1 Glide Left 3 gl3 1.2 Move left by 3 and down by 1 Glide Right 1 gr1 0.7 Move right by 1 and down by 1 Glide Right 2 gr2 1.0 Move right by 2 and down by 1 Glide Right 3 gr3 1.2 Move right by 3 and down by 1 Current player must be above a Ladder or Air tile, and all tiles in the axis aligned rectangle enclosing both the current position and new position must be non-solid (i.e. Air or Ladder tile). See example below. Drop 1 d1 0.3 Move down by 1 Drop 2 d2 0.4 Move down by 2 Drop 3 d3 0.5 Move down by 3 Current player must be above a Ladder or air tile, and all cells in the line between the current position and new position must be non-solid (i.e. Air or Ladder tile). Example of glide action validity requirements for GLIDE RIGHT 2 (‘gr2’): Current Position Must be Non-Solid Must be Non-Solid Must be Non-Solid Must be Non-Solid New Position Page 3 COMP3702 The DragonGame AI Environment Interactive mode A good way to gain an understanding of the game is to play it. You can play the game to get a feel for how it works by launching an interactive game session from the terminal with the following command: $ python play_game.py.txt