Template:NPC Knowledge
NPC Knowledge
(See also PC Knowledge.) Likewise, the GM and the Adversary should not use knowledge that their characters could not logically possess. This is the main reason for having an Adversary in the first place...so the GM can't use his total knowledge of the PCs against them. The warnings under PC Knowledge apply equally to NPCs, but there are some additional things to watch out for:
Objectives of the party. The GM knows the players' true objectives; the Adversary may know. But when he plays "ignorant" characters, he must roleplay his ignorance. This might mean that an NPC acts hostile when he "should" be friendly, or vice versa. It also means that when the party sneaks into the castle, the guards can't all rush to protect the treasure room. They don't know for sure where the PCs are going!
Abilities of the party. All NPCs – especially adversary characters – should react according to the apparent strength of the party. A simple example: if the PCs are exploring a dungeon populated by roving bands of orcs, each new band should find out the hard way that the party's wizard uses the Explosive Fireball spell – until some orc escapes to spread the word.
Special weaknesses of the party. If (for instance) two members of the party are deathly afraid of snakes, the adversary characters shouldn't know this unless there is a way they could have found out. In fact, the GM shouldn't tell the Adversary things like this in the first place. Let him find out for himself! But even after he finds out, he can't use this sort of fact unless he is playing a foe who should know.