Jianguo Ding / RAGBack to home

Screenshots show the Chinese version. The game is available in English, Japanese and Chinese. Open the game directly ↗

01 / A real problem

Why do we need RAG?

Imagine a company
with a large collection of internal documents.

Employees want to ask AI directly,
instead of searching through every document themselves.

A question at work

“Our product has this problem.
What should we do?”
Product manualsIncident recordsLatest maintenance notices

An LLM does not inherently know these documents.
It may not have the latest information either.

How can the answer use this external information?

02 / The basic idea

Find information first. Then answer.

RAG (retrieval-augmented generation) brings external information into the answering process.

  1. UserAsk a questionWhat needs to be resolved?
  2. RetrievalFind relevant informationSearch external sources
  3. Input to the LLMQuestion + retrieved informationGive the model material to refer to
  4. LLMGenerate an answerAnswer using this information

One detail deserves attention

Finding “similar” material
does not necessarily mean finding material that “helps answer” the question.

Next, make the process of finding information visible.

03 / From explanation to play

Now it is your turn to find information.

Let a small robot carry the documents,
so you can see what your choices change.

Set complex models and databases aside for now.
Small questions from a tea shop simplify the real-world setting.

The robot
The character you control carries the information you select. It is neither the LLM nor a complete retrieval system.
Documents on the desks
External information you can look up, such as opening hours and drink prices.
The LLM reply desk
The answerer appears in level 4. It receives the question and documents and writes a reply.
Actual Chinese game screenshot; the playable game also supports English.
Actual level 4 screenshot · cropped to the room
Open the image to see the full original screenshot.

This is a deterministic teaching simulation.
Documents, retrieval results and replies are prewritten. No real embedding, retrieval or LLM runs here.

Start by choosing a document. The answerer appears later.

04 / Into the existing game

First, find the right page.

Actual Chinese game screenshot; the playable game also supports English.
Actual level 1 · task and controls in the mobile screenshot

Your task

A customer asks: “What time do you open?”

  1. Read the current question.First identify the information the customer needs.
  2. Select “Opening hours” on the desk.On mobile, inspect it and then choose the pick-up action. On desktop, click to pick it up.
  3. Hand the document to the customer.On mobile, use the hand-over action; on desktop, click the delivery window. The game gives feedback and a level recap.

In levels 1–3, choose documents and hand them directly to the customer.
The reply desk appears in level 4; retrieval tools begin in level 5. If you choose the wrong information, use the feedback to try again.

Start by choosing one document.
The game opens in a new tab. This introduction stays open.

05 / Looking back · From play to understanding

A good answer depends
on more than the model.

Remember the document
that ranked first?

In level 5, “New drink promo” mentioned pearl milk tea,
but did not provide the information needed to answer the price question.

Even if the answerer can understand the question,
unsuitable material or missing evidence can still lead to failure.

So designing RAG means considering not only the LLM,
but also how information is prepared and retrieved.

The documents, candidate order and replies in this game are prewritten. Real RAG also involves embeddings, chunking and retrieval strategies. This experience only builds an intuition.

Actual Chinese level 5 ranking panel: the question asks the price of pearl milk tea. The first candidate lacks the price; the fourth candidate, the drink price list, provides 18 yuan.
Actual level 5 screenshot · candidate ranking panel
Mentioning the same drink does not mean answering its price.