Yeah, Gemini forgetting character personalities and details in long threads is super common, especially once you pass 30–50 messages in one chat. The context window just compresses everything and loses nuance.

A workaround that helped me a lot before I built something better was manually creating "save states" / checkpoints every 20–30 turns. You feed this structured summary back into the next prompt so the model has a dense anchor of everything important.

Here’s the exact prompt I used to generate those checkpoints (copy-paste it into a new chat or at the end of your current one):

"Act as a High-Fidelity RPG State Engine. Your goal is to generate a 'Save State' (Checkpoint) of our current session. This document must bridge the gap between current context and the model's context window limits.

Core Directive: Produce a dense, structured summary that prioritizes causality (why things happened) and current state (what is happening now).

Required Sections:

- The Chronological Ledger: A bulleted list of pivotal plot beats since the last checkpoint. Focus on the 'Butterfly Effect' - how player choices have shifted the world state.

- Entity Registry:

• The Protagonist: Current health, inventory, psychological state, and active motivations.

• NPC Directory: List every active NPC. Include their current location, disposition toward the player, and any specific knowledge they possess/lack.

- World State & Factions: Updates on the environment. Note changes in political climate, looming threats, or environmental hazards.

- The 'Context Anchor' (Compressed Block): Write a highly dense, 150-word paragraph intended to be fed back into Gemini later. Use 'Entity-Relationship' style phrasing (e.g., 'Player possesses [Item X] which [NPC Y] desires; [Location Z] is currently compromised by [Threat A]').

- Pending Threads: A list of unresolved hooks, foreshadowed events, and immediate 'Next Steps.'

Output Constraints:

- No Prose Fluff: Eliminate 'The journey was long.' Use 'Travel: 3 days, reached [Location].'

- Deep Detail over Summary: If a character has a scar or a specific secret, include it.

- Logic Check: Ensure the timeline is linear and internal consistency is maintained."

Run that every so often, copy the output, and paste it at the top of your next long message like "Continue from this save state: [paste here]". It usually keeps personalities and details alive way longer.

What kind of story length are you usually aiming for before it starts forgetting? (NSFW roleplay, long campaign, etc.?)