Is the source material suitable for role-playing?Edit
The first consideration is whether the source would make an entertaining adventure. I enjoy Scrubs and The Big Bang Theory, but they wouldn’t make good RPGs. They are character-driven: the events are small in role-playing terms, and the enjoyment comes from the character interaction. Imagine changing one player-character’s shift in your game so that he can’t offer another a lift to work – would that spark off a full and enjoyable evening’s adventuring? If so, I envy you your players!
So the first requirement is that the source provides incidents which make good RPG scenarios. Most action-based sources do that nicely, so next is whether the source’s characters and situations are suitable for your role-playing group.
Firstly, are the characters balanced? The problem with a Dr Who™ campaign is that you have one character who is 900 years old with an education in technologies and cosmology way beyond human experience. Anyone else is a standard Earthling – not a balanced party. If the Doctor is an NPC, the GM’s character dominates the party because of that gap.
A campaign involving the Doctor himself would suit a single player and GM, not a group of adventurers. But in any Dr Who™ campaign the companion(s) would not be the ‘stars’, knowing their status relative to the Doctor. If you want to use the Doctor’s universe without him dominating the scenarios, a UNIT™ or Torchwood™ campaign, where the Doctor appears peripherally, is a much better option. However, it does confine the adventures to present-day Earth (or even Cardiff!), which may restrict the adventures you want to run.
Finally, is the genre right for your game? If your players love subtle games with mystery investigations, unravelling a tangled web of deceit by questioning multiple suspects and witnesses, they won’t enjoy a Starship Troopers™ campaign. Conversely, bash’n’loot types won’t go for the investigative aspects and psychological tension of Call of Cthulhu™. Only you can decide whether a particular campaign will suit your players.