Can NPCs really die?

I'm in the middle of a Blood Moon night and fighting horde of monsters. In a Blood Moon wiki's page, it is written that:

This can put the player's home and NPCs in peril.

In fact I see that zombies and eyes attack NPCs and do some damage. But do NPCs can really die if I do not defend them? And if the answer is yes will they come back at some point?

3 Answers

According to the wiki here:

If any NPC were to die (eg. During a Blood Moon) they will simply return after a period of time, as long as no other NPCs moves in during their time of death.

In episode 21 of Red & Blue's preview of Terraria (at about 2:45), they suffer a zombie attack in which several of their NPCs die. In later episodes, however, the NPCs have returned.

Yes, NPCs can die, but not permanently. If an NPC dies, then the game just acts as if the NPC had never been in the house in the first place. For example, if your Guide dies, another Guide may move into a house. This is the same for all NPCs, except an NPC having previously moved in does not automatically fulfill the criteria for them to move in again. For example, if a Merchant dies, they will be able to move in once the "50 silver" criteria has been met again.