> For the complete documentation index, see [llms.txt](https://wiki.osro-revo.gg/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://wiki.osro-revo.gg/dungeons-and-instances/sunken-tower.md).

# Sunken Tower

<figure><img src="/files/SkBWxfJA3ah1eSgIl1vw" alt=""><figcaption></figcaption></figure>

A meteor struck the **Endless Tower**, sinking its halls beneath the sea. The monsters remain and they’re getting stronger. **Leticia** needs your party to clear the **Sunken Tower** before the corruption spreads to the city.

***

### How to Start:

| Step | What to do                    | Details                                                 |
| ---- | ----------------------------- | ------------------------------------------------------- |
| 1    | Form a party                  | **Minimum:** 2 members (solo not allowed)               |
| 2    | Meet Leticia                  | **Map/Coords:** `alberta 214,74`                        |
| 3    | Party Leader talks to Leticia | Only the **party leader** can create/enter the instance |
| 4    | Pick a Mode                   | **EXP Mode** or **EXP+Coin Mode**                       |
| 5    | Pay fee                       | **20,000 Zeny per member**                              |

***

### Requirements & Entry Rules:

| Requirement    |                                    Value |
| -------------- | ---------------------------------------: |
| **Base Level** |         **40–99** (bracketed; see below) |
| **Party size** |                           **2+ members** |
| **Fee**        |               **20,000 Zeny per member** |
| **Cooldown**   |        **72 hours (3 days)** per account |
| **Duration**   | **60 minutes** (with countdown warnings) |
| **Map**        |              `1@ch_u` (Memorial Dungeon) |

{% hint style="warning" %}
If someone in the party is **offline**, **lacks Zeny**, or **out of level range;** creation fails.
{% endhint %}

***

### Level Brackets & Rank:

Your **party’s bracket** is determined by the leader’s Base Level at creation:

| Bracket | Levels | Rank (internal) |
| ------- | -----: | --------------: |
| **A**   |  40–59 |               0 |
| **B**   |  60–79 |               1 |
| **C**   |  80–99 |               2 |

{% hint style="success" %}
This rank affects monster stats, EXP, coin rates, and scaling.
{% endhint %}

***

### Modes:

| Mode                | What you get                                                                             |
| ------------------- | ---------------------------------------------------------------------------------------- |
| **EXP Mode**        | Experience rewards only                                                                  |
| **EXP + Coin Mode** | Experience rewards **plus** a chance to earn **Event Costume Coins** per 5th floor clear |

{% hint style="info" %}
You select the mode during creation. (EXP is always awarded; Coin is added if chosen.)
{% endhint %}

***

### Difficulty (inside the instance):

Talk to **Leticia** inside (`1@ch_u 8,55`) to **change difficulty** at any time:

| Difficulty | Cost to change                         | Effects                                          |
| ---------- | -------------------------------------- | ------------------------------------------------ |
| 1–5        | **1 × Sunken Tower Ticket** per change | More & tougher mobs, higher EXP & coin potential |

{% hint style="warning" %}
If you pick the same difficulty you’re already on, the change is rejected without consuming a ticket.
{% endhint %}

***

### Instance Flow:

* **Up to 150 floors**, repeating a **5-floor cycle** of spawn areas.
* On each floor start, Leticia announces buffs/theme (random element influences the run).
* Each floor spawns **20 + (5 × Difficulty)** randomized mobs from a large pool.
* **Every 5th floor** (i.e., when `floor % 5 == 4`) you can **claim rewards** before proceeding.

**Party leader** uses any **Dimensional Portal** to advance when the floor is clear.

***

### Rewards (every 5 floors):

| Reward Type             | How it works                                       |
| ----------------------- | -------------------------------------------------- |
| **Base EXP / Job EXP**  | Awarded to each member who claims on the 5th floor |
| **Event Costume Coins** | Chance per claim in **EXP+Coin Mode** only         |

**Coin chance & amount scale** with **Rank** and **Difficulty**:

* **Coin drop chance (%):** `15 + (5 × Rank) + (5 × (Difficulty − 1))`
* **Coin amount:** random between `5 + 3 × (Difficulty − 1)` and `7 + 3 × (Difficulty − 1)`

> The instance tracks how many party members have claimed (to avoid leaving people behind). The leader can **force-advance** (skips unclaimed rewards).

***

### Scaling Snapshot (what increases with Rank/Difficulty):

* **Monster Stats:** HP/ATK/HIT scale with Rank & Difficulty; random **Size**, **Race**, and **Element** per spawn keep fights varied.
* **EXP:**
  * **Bonus EXP:** increases with Rank; further boosted by Difficulty
  * **Mob EXP & Job EXP:** scale similarly; **Job = 80% of Mob**

***