Landlord Scam can refer to several possible con games that involve making money off of a renter or landlord.
- The scamster rents an apartment with an out of state check, lives in it for a few days, then claims it has roaches (he puts the roaches there) moves out, stops payment on the check before it clears. 
- The con man notices a vacant property (or takes a short-term sublet on a property) and places ads that the property is for rent. They hold an open house, or take calls via the ad. They set the rent cheap so plenty of fish will bite, and collect a deposit and first and last month's rent from every person that comes to look at the place. On the first of the month, a dozen families show up, all expecting to move into the property. The con man is long gone with their money, and none of the families have the legal right to move into the house since he never owned it. 
- A landlord rents out a building that he knows is condemned, sold, or scheduled for demolition in a few months. He doesn't tell the tenants who rent it from him, explaining instead that he's moving out of state, or even out of the country. He collects rent via the mail or a drop-off system, while relocating to a place unlikely to extradite him. Since he intends to actually rent this out for at least a few months, the rent is probably comparable to other properties in the area (low enough to attract a renter, but not so low as to arouse suspicion). One day, the renters are surprised by the sound of a demolition crew or new developers showing up. 
Game and Story Use
- The first version listed could be used by minor villain to save themselves Hotel costs. The check might not be canceled, it might be a stolen check instead.
- The other two examples are even worse, as the victim is not only out a good deal of money, they also have nowhere to live and nowhere to store their belongings. If moving expenses were incurred as well, they may be in a lot of danger.
- Strikes me as a very cruel and spiteful thing to do to someone. The con man is either very evil, very desperate, or has an axe to grind against the specific marks he targeted.
- Quite often not spiteful … just callous. Most con artists have no personal animosity towards their marks, just contempt and a total lack of empathy. Of course in the right era, racism or some other kind of prejudice might enter into it, especially if it makes it hard for the victims to seek justice. Preying on refugees is a time honoured tradition amongst people on the outskirts of conflict zones.
- If the Big Bad finds out the PCs are looking to set up a new HQ, they could be in trouble.