When interrogating an NPC for any reason, a Stalker can acquire special knowledge about the NPC in one (but not both) of the following ways:
By making a successful Intelligence check (use half the Intelligence score, rounded up), the Stalker can determine the general alignment of the NPC. If successful, the Stalker learns the good-evil component of the NPC's alignment (good, neutral, or evil).
The Stalker can ascertain the NPC's honesty. The DM secretly makes an Intelligence check for the Stalker. If the check fails, the DM tells the Stalker nothing about the honesty of the NPC. The Stalker must make up his own mind about the NPC's reliability based on the NPC's responses.
If the check succeeds and the NPC is being honest with the Stalker, the DM tells the Stalker that the NPC is telling the truth to the best of his knowledge. A successful check in no way compels the NPC to reveal any information to the Stalker. The NPC may refuse to cooperate, but the Stalker is assured of the truthfulness of anything the NPC decides to share (note that the NPC may still pass along unreliable information that he believes to be true).
If the check succeeds, and the NPC is being dishonest with the Stalker, the DM tells the Stalker that the NPC may be lying. It's up to the Stalker to separate the truth from the lies; a successful check only tells him that he shouldn't take everything the NPC says at face value.
When a Stalker reaches 10th level, he acquires a limited photographic memory, enabling him to recall details about anything he's seen or heard since achieving 10th level. He can recall a fragment of a conversation, conjure up a mental image of a place he's visited, or remember words on a printed page. To use this ability, the DM secretly makes an Intelligence check for the Stalker, with a -2 penalty. If the roll fails, the memory is too vague to be of any use to the Stalker. If the roll succeeds, the DM tells the Stalker what he wishes to remember. If the roll is a natural 20, the DM gives the Stalker intentionally misleading information about whatever he's trying to remember (a room, for instance, is incorrectly recalled as having a locked window or mysterious claw marks on the walls). Because of the mental stress involved, this ability can be used only once per day.
Neither lawbreakers nor outlaws appreciate snoops. Typically, the harshest possible penalties are reserved for captured Stalkers. Should a band of orcs or goblins realize that a Stalker is in their midst, they're likely to chase him down and beat him mercilessly. A Stalker caught lurking in private residence will probably be prosecuted to the fullest extent of the law. An otherwise friendly NPC may be less likely to cooperate with the party if he recognizes one of the members as a Stalker.
The Warden works for a noble, king, or wealthy land-owner, and is charged with managing and protecting a tract of land owned by his overlord. He keeps his overlord's land free of monsters, guards against spies and trespassers, intervenes when natural disasters occur, and sees to the welfare of the animal population. While a Warden may operate alone, making decisions as he sees fit, he ultimately answers to a higher authority.