Disclaimer: as the source code of Dilbert's Desktop Games is not available, much of the below was determined primarily from qualitative testing, hence the lack of precision in what is described.
NPCs that can travel through doors (Alice, the Boss) and through doors and elevators (Bill, Police, Phil, Dogbert) will perform such a travel in order to get to the same floor as Dilbert. Note the distinction of 'the same floor' rather than 'the same room' — if Dilbert is in one room on a floor and a NPC can take a path directly to another room on the same floor, they will be satisfied with taking that path. Should you be in the middle of an anti-gravity fly, until Dilbert lands the NPC will consider him to be on the floor on which the fly started.
The point at which a NPC makes the decision to take a door to the same floor as Dilbert can usually be determined by the point at which they start an uninterrupted walk toward the source door (as opposed to continuing their aimless direction switching). At the point that decision is made, nothing will prevent the NPC from abandoning that decision — even Dilbert switching floors himself. Note also that NPCs that can only use doors can only map out paths one decision deep to Dilbert's floor — if a door-only NPC could take a series of two doors to get to Dilbert's floor, they will be unable to make such a decision.
The point at which an elevator-capable NPC makes the decision to take an elevator can be similarly determined. The difference with elevator decisions is that the floor to which the NPC will take that elevator is not decided until the doors to the elevator start closing, making the decision to use the elevator and the decision where to exit the elevator two separate decisions. As such, if Dilbert moves to the same floor as the NPC in between the NPC calling the elevator and the elevator doors closing, the NPC will abandon the elevator as its doors close. Similar to door decisions, nothing will prevent an elevator NPC from altering their decision of to which floor to exit once the elevator doors close, even Dilbert changing floors.
If Dilbert has stealth business suit engaged, NPCs able to follow Dilbert will be incapable of deciding to follow him. As such, in certain situations it may be advantageous to burn through usages of the suit strategically to prevent NPCs from calling elevators, even if no NPCs are around to hurt Dilbert in the moment.
If Dilbert has deployed one or more clones on a different floor from himself, NPCs capable of deciding to follow Dilbert will prioritize following the clone(s) over Dilbert himself. That is, if an aggressing NPC has the capability to decide either to follow Dilbert or to follow a clone, they will follow the clone. If the NPC can only decide to follow Dilbert, though — or if they are already on Dilbert's floor — they will still follow Dilbert.
This NPC behavior quirk can actually be used to save time under certain conditions, such as to cause elevator-capable NPCs to exit at a floor closer to your final location to reduce the travel time of the elevator on level clear, or to keep an elevator-capable NPC occupied on their current floor for the duration of the level with a clone in a separate room on the same floor. Some potential examples:
- Hardware Testing (25-28): leave a clone in the small room on floor 27 to keep Bill from calling the elevator for the duration of the level
- Firmware Testing (33-36): leave a clone in the elevator room on floor 35 so that if Bill follows Dilbert, the elevator is only a floor away from Dilbert's final location rather than two floors should Bill decide where to follow when Dilbert is getting the final box of donuts
- Sales (81-84): spam some clones at the start of the level to aggress Bill to floor 81 so that the elevator is where it needs to be when Dilbert returns from his donut trek
- Executive Suites (117-120): leave a clone at the start of the level to aggress Dogbert to floor 117 so that, should Dogbert decide where to follow when Dilbert is getting the donuts on 118, the elevator will still go to 117 where Dilbert needs it
This NPC behavior quirk can also potentially yield time loss if sufficient care isn't taken, particularly on levels with Police NPCs, as, for example, a clone left on the bottom floor will cause NPCs to elevator to the bottom floor as you clear donuts on the upper floors, making the elevator's final travel time to Dilbert longer. A particularly risky strategy to counter this annoyance is to leave a clone upon exiting the elevator then immediately enter the elevator again, then repeat instantly entering the elevator (leaving clones as needed) ad nauseam until the clones have picked up all the donuts and you can clear the level, thus continually occupying the elevator such that the NPCs can't use it — a strategy the author of this guide likes to refer to as 'scum strats'.
