Question: I'm looking for a tool that can help me generate unique character backstories for my tabletop RPG campaign.

If you want a tool to create random character backstories for your tabletop RPG campaign, LitRPG Adventures is a good option. This general-purpose system uses AI tools like OpenAI's GPT-3.5 and DALLE3 to create game material, including character backstories, random dungeons and other elements. With a library of more than 100,000 entries and several pricing tiers, it's a good tool for whatever campaign setting you have in mind, from traditional fantasy to sci-fi.

Another option is Spawn, geared specifically for Dungeons & Dragons (D&D) fans. Spawn can generate fully fleshed-out characters in less than a minute, including ability scores and inventory details. It's a good way to save some prep time and get to the good stuff about your campaign.

For a more general writing environment that includes character creation, Novelcrafter offers a range of tools. Its Codex tool lets you store and track story elements, so you can keep track of character lore and other details. With AI tools and different writing modes, it can help you with outlining, writing and editing.

If you need more storytelling tools, StoryNest.ai offers an AI-powered service to create compelling stories and interactive narratives. It includes character creation tools, world-building tools and AI-assisted editing, so it's a good option for developing your RPG's story and characters.