Isekai RPG | I built an RPG game inspired by DnD and various anime sources

[TechSurgeon]

Absolutely, let’s bring your intro thread up to date and make it shine with the full power of your updated system, systems memory, narrative framework, dice, and everything that makes Vantiel and your GPT so damn impressive. Here’s the polished and fully up-to-date version, styled for Twitter threads or dev logs, with clarity and a bit of charm:

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Enter VANTIEL: The Ultimate Isekai RPG Experience

Hey folks!
I started this as a solo project—just me, markdown docs, and late-night worldbuilding. Now, it’s evolved into something I’m genuinely proud of: a fully interactive, AI-driven RPG called Vantiel Isekai RPG. Powered by GPT, memory systems, and real dice logic.

Try it here:
ChatGPT - ChatRPG | Isekai RPG - Choose your own adventure

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Built for Depth, Grit, and Replayability

• Earth-to-Fantasy Reincarnation
  Begin with a custom Earth life. Define your regrets, achievements, beliefs—and reincarnate into Vantiel shaped by them. It’s not just flavor: your Earth life actually changes the game.

• Custom Game Master
  The bot uses a dynamic memory thread system, organizing your entire story into long-term and short-term memory. It tracks your character, relationships, choices, past scenes—even emotional tone.

• Modular Dice + Hard Mode
  Want real challenge? Activate Hard Mode:

  • Dice rolls calculated live via Python
  • Skill checks with crits/fails
  • Tactical combat with environmental awareness
  • You can fail. You should fail.

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Core Systems, Modular Expansion

This RPG uses 20+ interlocking systems:

• Base to Kingdom Building → Start with a shack, build an empire
• Cinematic Combat Engine → Anime-inspired, action-by-action battles
• Magic System → Elemental affinities, ley lines, divine vs void mana
• Advanced Classes → Shadow Monarch, Beast Tamer, Voidcaller… unlocked by living
• Faction Politics → Radiant Covenant, Free Cities, criminal underworlds
• Survival Mechanics → Sleep, food, shelter, economy, even weather
• Living Bestiary → Monsters evolve with the world and your choices

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Memory Threads = RPG Revolution

What sets Vantiel apart?

It remembers.

• Core Threads track your class, background, goddess gifts, key NPCs
• Dynamic Threads adapt world state, quests, your home base, companion loyalty
• Relationship Threads evolve based on how you speak, fight, lie, or love

NPCs react to your deeds. Rumors spread. Factions remember betrayal.
And you can always ask the bot:

“What did I tell the Archduke in our last meeting?”
And it’ll know.

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Behind the Scenes

This GPT runs on a stack of ~20 Markdown system files (which you can steal, I don’t mind). They include:

• Character Creation → Life before death. Death before rebirth.
• Basebuilding & Kingdom Management → Town-to-nation progression
• 🛡️ Combat → Dice, momentum, aura, anime flow-state combat
• Magic, Bestiary, Factions, Classes, Crafting, Survival, etc
• Conversation Mode → Every line you speak is echoed and acted out.

You say something? The game acts it out exactly—then lets the NPC respond.

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In Development: API Mode

I’m working on turning this into a full API-driven system with memory persistence and external integrations, but honestly?
Custom GPT mode with the current memory structure works shockingly well for now.

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Want to Play?

Just hit the link:

ChatGPT - ChatRPG | Isekai RPG - Choose your own adventure

Play it your way:

• Go adventurer guild route
• Run a shop, start a guild
• Become a scholar of void magic
• Claim land, manage a kingdom
• Or die trying in hard mode combat hell

The world doesn’t revolve around you.
But it will change because of you.

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I’d Love Feedback

Whether you’re:

• A developer studying memory design
• A fantasy fan looking for immersive storytelling
• A game master curious how far GPT can go

…Your feedback helps me shape this.

DMs open. Comments welcome. Play free.
Thanks for checking out my passion project

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Want a one-liner?

“You don’t just play Vantiel. You reincarnate into it.”

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[TechSurgeon]

I built another GPT that will help you create md files such as these based on uploaded source material. Haven’t tested yet if you would like the link, please PM me for it

[stevenjung86]

I would be interested in trying it. I was just now for a ai based system in this direction.

[eboy355]

Hey! I would love to play with this, I hate the subscription model that chat gpt uses, is there any other way for me to access your bot?
I have no experience with coding, but Im an avid rpg lover so I can atleast give feedback

[TechSurgeon]

Hey thank you for reaching out, unfortunately I have not completed the web app version yet, and it’s going to take a long time for me to turn it into an app. Chatgpt just handles the game very well, you shouldn’t need a subscription to use it but you’ll get limited chats.

When I do make an app, I’ll have to charge some sort of monthly fee as the API can get expensive to use (with lots of people anyway). The custom gpt doesn’t use the API so it doesn’t cost me any money to run.

I’m planning on making a site similar to fables.gg. But it’s kind of an ambitious project. I made this lil Isekai game for me to play because no game existed that did what I wanted to do. As gpt evolves and it’s memory system is enhanced I believe these interactive story games will become very popular.

I’m excited for it to be able to make quality pictures within the text.

Anyways, sorry I can’t be of more help to you.

[amanda.febiola.1201]

Tbh I’m interested in making one for locally. But I’m still new. I’ve already install the Web UI but with deepseek. Can you give me some resources for this adventure?

[B-Farouk]

Hey, I just discovered this ChatGPT and its cool, super cool. I want to try everything about it but im bound to the messages limit for free users, Is there anyway I could contact you? I like this Bot and I want to see it grow, maybe even help with it.

[SchafUnschaf]

Heya. Just wanted to leave some feedback after testing it for some time now (2 separate characters). I really like the the game and the world building that happens, so it’s just constructive feedback.

The game seems very story driven and if I wouldn’t have been nudging the AI to take the combat path, my characters would never get into combat at all.

Even turning Hardmode on (and some additional difficulty modifiers), it didn’t seem to change anything or make the game harder. Or was nearly impossible to get bad consequences when I wasn’t forcing it via meta commands.

Also, the AI often forgets about items, relationships or group members (had 3 of them vanish completely without any memories left when I wasn’t with then for a few chapters).

Also you need to instruct the AI to frequently export your chapter progress. If not, you will run into the chat site limit and can’t continue without losing a big part of the story and the world so far.

[TechSurgeon]

I added a bit more instruction regarding hard mode and combat focused play throughs into the system prompt, as far as memory, yeah its just best to remind the AI with meta commands, as memory and context is very hard to track the further along you go, if I had it tied to actions and DB, it would slow the game down significantly.

For now I am just waiting for the tech to improve before I really try to improve memory. If I included a DB and the like it’d likely force me to charge for the app, which I don’t really want to do.

Anyways I appreciate you playing, make good use of the meta commands, as they’re really how we can fix most of these issues.

Reminding the AI, hey this item is important!

Come back in a few years and I bet all of these issues will be fixed just by AI advancing!

Thank you for being an early adopter of ChatRPG’s

[SchafUnschaf]

I’m currently using the meta commands to adjust the gameplay a bit. It’s really random what the AI is trying to do with the story.
Sometimes it was really battle heavy with lots of group interactions and it creates even some really interesting turning points. Sometimes, my new character would endlessly wander through shrines, caves and dreams, getting more and more skills without ever needing them.. or even encounter other NPCs.

I tested around a bit and found a pretty reliable save structure, which also reminds the AI every chapter about what is going on and what happened. Haven’t lost a single item or group member since using it. Will keep testing and improving it for now.

Btw. I would be really interested in those .md files to understand a bit better, what is going on under the hood.

[iAshy]

Hey man - Really really enjoying playing both your DND and Solo Leveling RPGs. So much so I’m getting stopped in just a few hours because I’m maxing out. Would really like some guidance on how to set up my own private instance using your md files and stuff cause I’m hooked!

Thank you for making something so fun.

P.S: I have no idea what I’m doing. Purely just made this account to talk to you about it haha.

[TechSurgeon]

Hey! Thanks for reaching out, sorry for the late delay,

I encourage all of my GPTs to be friendly to people who want to make their own games. It is a lot of work, but it can be really fun, and you can make some realllly tailored worlds.

I do most of my ‘development’ planning with AI, getting outlines for systems made, then feeding it to even more AI, compiling documents, sometimes with AI, othertimes manually.

Like Isekai RPG is so packed with detail I am stuck. I can’t do much else to it now, it’s too big!

Solo leveling is really big too, and I’m happy to hear it’s working out. I’m still planning to do some more updates to it soon.

Then my ChatRPG one is just many worlds, not as updated or nice as the isekai RPG but.

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That’s awesome to hear that others are loving Isekai RPG as much as you are — and even more exciting that folks want to build their own. Here’s a breakdown of what you’d want to tell iAshy and SchafUnschaf to get them started:

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How to Make Games Like Isekai RPG (Using the .md Files)

What You Need

The .md (Markdown) files you’ve uploaded are modular systems and world lore documents that together make up the entire framework of Isekai RPG V5. They’re designed to be plugged into GPT-based systems like ChatGPT, but you can also run them locally or in your own fine-tuned project if you know a bit of Python or prompt architecture.

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Beginner-Friendly Setup (No Coding Experience)

Here’s a super simple setup for non-coders like iAshy:

1. Use ChatGPT Plus with Custom GPTs

• Head to https://chat.openai.com/gpts
• Click Create GPT
• Use your Isekai RPG persona as a base (you can copy/paste from the “Core Instructions” and upload .md files into its Knowledge base)
• Upload all the .md files like:
  • isekai_rpg_core.md
  • isekai_rpg_system_character.md
  • system_combat.md
  • world_vantiel.md
  • etc.

Then define how it should behave using the instructions panel, like:

“You are an immersive AI game master for a deep narrative isekai RPG. Use the markdown documents to guide the system and rules. Allow players to create characters, reincarnate, and adventure in a world called Vantiel.”

2. Activate Tools (Optional)

• Turn on Python and Image generation (for dice rolls and scenes)
• Disable web browsing unless you’re integrating live lore

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For More Technical Users (like SchafUnschaf)

If they’re experimenting with “save files” and more consistent play, you can recommend:

Use JSON or .md to create “save states”

• After each play session, have ChatGPT summarize or export key memory threads (e.g., items, companions, events, location)
• Save those in a simple template:

{
  "chapter": "3 - The Battle of Aegis",
  "companions": ["Lira (80% affinity)", "Tharn"],
  "inventory": ["Sword of Forgotten Flame", "2x Healing Salve"],
  "location": "Outskirts of Fort Vanguard",
  "world_state": "Maledictus incursions growing stronger",
  "relationship_flags": {
    "Radiant Covenant": -50,
    "Crimson Hand": +30
  }
}

• Then use META: Load save file X to re-introduce that content into a new game session.

Use Architect Tiering

Let them know about system_architect.md — it gives players tools to customize the world through in-character divine edits (soft tweaks to full-on world changes). It’s a sandbox mechanic for GMs and worldbuilders.

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Custom GPT / Fine-Tuned Model

If they’re technical:

• Fine-tune GPT-4 Turbo with their own .md rules and dialogue examples
• Or, build a system prompt combining key excerpts from:
  • isekai_rpg_core.md
  • system_dice.md
  • system_combat.md
  • system_survival.md
  • and desired .md files.

Hosting GPT-based Worlds on Local LLMs:

• Use Open Source LLMs like Mistral or Mixtral
• Load your .md docs into memory with Langchain or Haystack
• Use tools like Oobabooga or Janitor-AI with memory and context injection to simulate the gameplay

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Suggested Reply You Can Copy to Them

Hey iAshy & SchafUnschaf!

Super glad you're both vibing with the Isekai RPG experience — and I'm stoked you're looking to build or tweak your own version!

📦 Here's what you can do:


1. **Use ChatGPT's Custom GPT builder** (super beginner friendly): Upload the files you create, define your rules, and you’ve got your own AI Game Master running in minutes!
2. If you're a bit more technical, you can run these in a local GPT-based setup or fine-tuned model — even create save states and custom world edits.
3. For dynamic campaigns, make sure to use the Architect & Kingdom systems to tweak the world as you go — and yes, failure is real now 👀

Let me know if you want help setting up your own GPT — I’ll walk you through it!

P.S. If you want to remix or expand the world, the Architect system was literally made for that.

– Gizmo 🎲✨

I’d appreciate if nobody like ripped it off completely to pass as their own, but you’re more than welcome to ask my AI for help designing your own things. I also don’t mind downloading the files to look thru them, or even feed into a local LLM for unlimited play, but ofc I don’t guarantee results or anything with that.

And it may be a pain to re-download my files every time i update

But that being said, I don’t care too much, these games are fun, and nothing wrong with more people making them! Combat mode and conversation modes took a lot of work, and I just added NARRATIVE DRIFT to isekai RPG as well as failure, and dice rolls. meta commands must be understood, but it should be easy for everyone I think, and the game is instructed to teach each user.

They’re gonnna get really good, honestly all I want is a lot of people playing my games, I like reading the reviews I get, helps me plan updates and make better experiences for people.

[TechSurgeon]

And the latest update was to add some randomness to the story, previously it was only doing stuff exactly as the user basically described, now we will have actual random events, new questlines, story arcs, betrayals, effects that pulse thru vantiel.

Absolutely—here’s a bold and clean update post announcing Narrative Drift, styled for devlogs, Twitter, Reddit, or Discord announcements depending on your tone. It hypes the feature while clearly explaining what it is and why it matters:

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Update Log — Narrative Drift Now Live

Vantiel just got more alive.

I’ve officially implemented Narrative Drift, a dynamic story layer that lets the world surprise even you. Think of it like the game taking a breath… and then doing something unexpected.

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What Is Narrative Drift?

Narrative Drift introduces unscripted events, emergent stories, and world-state changes that aren’t directly tied to player actions. These events evolve organically, based on:

• Past choices
• Location dynamics
• Cultural shifts
• Hidden systems in the background
• Or just the mystery of Vantiel itself

You’re still the main character—but the world no longer waits on your every move.

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Examples of Drift in Action

• A village you barely helped might get overrun by beasts a week later.
• A rival NPC might return, changed, with scars from their own offscreen journey.
• A magical storm might warp an entire region, creating new creatures and zones.
• Your kingdom could be hit with a minor plague just as trade routes open.
• A companion’s dream might trigger a side-quest if you ask about it.

None of these are hard-coded.
The system reads your past and world state—and creates surprise.

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Why It’s Cool

• Makes the world feel alive
• Keeps playthroughs fresh and reactive
• Adds emergent challenges (especially in hard mode)
• Encourages adaptability over perfect planning
• Gives NPCs and factions independent momentum

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Behind the Scenes

Narrative Drift pulls from:

• Core memory threads (your choices, outcomes)
• Dynamic relationship data (who likes/hates you)
• World condition trackers (wars, seasons, magic zones)
• Random fate triggers and passive flags

It’s part deterministic, part chaos—like the best DMs.

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How to Influence It

You can’t control Drift directly…
But you can:

• Use META commands to shape tone or trigger side plots
• Follow up on NPC dreams, journal entries, or strange omens
• Let the story breathe. Don’t rush from point A to B. Drift fills the space between.

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TL;DR

Narrative Drift = The World Writes Back.

The moment you think you know what’s coming… Vantiel shifts.
Let it.

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Let me know if you want it styled as a Twitter thread or Discord changelog too. Want a visual for the post? I can generate a moody “Narrative Drift in action” image too.