In Forgotten Realms: Demon Stone, the player directs a party of three characters - Fighter, Sorcerer and Rogue. The player controls one party member at a time - switching between them on the fly - while the other party members are controlled by the engine's sophisticated artificial intelligence. For example, when the player controls the Fighter, the Sorcerer and Rogue will continue to engage in combat, cast spells and assist the player in defeating all challengers. In many situations, the characters will be able to divide and conquer difficult objectives - while the Fighter holds back a horde of Yuan-Ti snakemen with brute force, the Sorcerer supports him with devastating ranged magic while the rogue sneaks above and behind them for a coup de grace. The player participates seamlessly in each critical moment as they are cinematically switched from one perspective to another.

This real-time, on-the-fly character switching design allows Forgotten Realms: Demon Stone to challenge players with innovative and compelling encounters. In true D&D fashion, each of the characters excels at a certain type of gameplay. The Fighter thrives in melee combat, the Sorcerer is excellent at ranged and magical combat and the Rogue excels at jumping, sneaking and disarming traps. Players will be continually tasked with choosing the best character for each challenge as well as using each character's gameplay specialty to maximum effect.