Although most of the main rules from 3.5 edition of "Dungeons & Dragons" are implemented, there are several exceptions. Some of them, such as applying a bonus to AC from the Dodge feat, are simplified to streamline play. Others, such as not letting prone characters attack, are implemented to reduce the number of required animations. The structure of the engine is also utilized, allowing encumbered characters to move at 3/4 their maximum rate, even if the resulting speed is not a whole number. Certain abilities, including Barbarian Rage, are modified to better flow with the game. A hybridization of some rules also occurred; the spell Doom is modified to reflect the first printing of the "Player's Handbook", and weapon sizes are a blend of 3 and 3.5 editions. The game also has two difficulty levels, Normal and Ironman, with the latter intended to more closely mimic the paper-and-pencil game.