# Promotions Protocol 2026 - Stages

> Arknights Endfield Promotions Protocol Space guide. SP generation mechanics, promotion material farming, and E1-E4 progression strategy.

Source: https://endfieldhub.org/guides/promotions-protocol
Published: 2026-02-09
Updated: 2026-02-09

Tacit Brook to Maelstrom - Promotion Materials Farming Strategy

Last updated: 2026-02-09

Complete guide to Promotions Protocol Space in Arknights: Endfield with 5 stages (Tacit Brook to Maelstrom), SP generation mechanics, team compositions, and sanity-efficient farming for Basic and Intermediate Promotion Materials.

## \*TL;DR - Key Points

* \* **Best early promos:** Stage 1-2 (Tacit Brook/Canal) - 40-50 Sanity for Basic materials
* \* **Best material density:** Stage 4-5 (Undercurrent/Maelstrom) - 70-80 Sanity for Intermediate materials
* \* **Mechanic:** Natural SP recovery very slow. Skill-based SP recovery greatly increased.
* \* **Location:** The Hub - accessible mid-game (Authority Level 25+)
* \* **Total Sanity:** 300 for all 5 stages
* \* **Primary rewards:** Promotion materials (Basic/Intermediate)

## Contents

## What is Promotions Protocol Space?

Promotions Protocol Space is a **combat challenge mode** located in The Hub that rewards promotion materials for elevating operator tiers (E1, E2, etc.). It's the primary source of upgrade materials for operator advancement.

### 5 Stages

Tacit Brook to Maelstrom - 40-80 Sanity each

### Basic Materials

8-34 Basic Promotion Materials per run

### Intermediate Materials

8-14 Intermediate Materials (Set B, Stages 3-5)

### Pro Tip: SP Mechanic

Natural SP recovery is very slow here. Build teams with multi-hit and combo-skill operators who generate SP actively through attacking and skill usage. Passive operators will struggle.

## Complete Stage Overview

| Stage | Name               | Sanity | Set A              | Set B           |
| ----- | ------------------ | ------ | ------------------ | --------------- |
| 1     | Tacit Brook        | 40     | 8 Basic Materials  | N/A             |
| 2     | Tacit Canal        | 50     | 14 Basic Materials | N/A             |
| 3     | Tacit Mere         | 60     | 20 Basic Materials | 8 Intermediate  |
| 4     | Tacit Undercurrent | 70     | 27 Basic Materials | 11 Intermediate |
| 5     | Tacit Maelstrom    | 80     | 34 Basic Materials | 14 Intermediate |

## Mechanics Breakdown - SP Recovery Altered

**Mechanic:** Natural SP recovery is much slower than normal. Skill-based SP recovery (from hitting enemies, combos, etc.) is greatly increased.

### What This Means

* • Operators naturally gain SP very slowly over time
* • Using skills generates SP much faster than usual
* • Active playstyle required - cannot rely on passive SP generation
* • Need operators with good SP generation skills

### How to Exploit

* • Build team with operators who have strong SP generation abilities
* • Prioritize skill usage and hitting enemies
* • Avoid passive operators who rely on natural SP recovery
* • Focus on high-attack-speed operators for consistent SP gain

### Pro Tip: Best Operators

Multi-hit operators (more hits = more SP), Combo-skill focused operators (combo skills generate SP), Physical/Heat operators (typically attack speed focused), and operators with SP-generating passive abilities work best here.

## Stage-by-Stage Walkthroughs

### Stage 1: Tacit Brook (40 Sanity) - Easy

Unlocks immediately upon discovering protocol space

Basic enemies, 2-3 waves

**Strategy:** Build SP-generation team with multi-hit and combo-skill operators. Use skills as soon as available. Active playstyle required.

Pro Tip:

Excellent Sanity efficiency for Basic Promotion Materials. Run 2-3 times daily for E1 materials. Bring operators with strong SP generation.

### Stage 2: Tacit Canal (50 Sanity) - Easy-Medium

Same enemies as Stage 1 with more HP

**Strategy:** Use Stage 1 team if clears are easy. Focus on SP generation. Active playstyle still essential.

**When to Move:** When Stage 1 clears are under 2 minutes and team generates SP consistently.

### Stage 3: Tacit Mere (60 Sanity) - Medium

First stage with Set B option

**Set A:** 20 Basic Promotion Materials

**Set B:** 8 Intermediate Promotion Materials

**Strategy:** Maximize SP generation with multi-hit team. Choose Set B when progressing to E2.

### Stage 4: Tacit Undercurrent (70 Sanity) - Hard

High HP enemies, 3-4 waves

**Set A:** 27 Basic, **Set B:** 11 Intermediate

**Recommended:** Operators Level 40+, E1 promoted team

**Strategy:** Build SP-heavy team with strong generation. Set B excellent for E2+ materials.

### Stage 5: Tacit Maelstrom (80 Sanity) - Very Hard

Very high HP enemies, 4-5 waves

**Set A:** 34 Basic, **Set B:** 14 Intermediate

**Recommended:** Operators Level 60+, E2-E3 promoted team

**Strategy:** Maximize SP generation. Aggressive playstyle required. Only attempt when consistently clearing Stage 4.

## Team Composition Guide

| Slot | Role     | Recommended                       | Priority |
| ---- | -------- | --------------------------------- | -------- |
| 1    | Main DPS | Multi-hit Physical/Heat operators | High     |
| 2    | Sub DPS  | Combo-skill focused operator      | High     |
| 3    | Support  | Healer or SP-buffer operator      | Medium   |
| 4    | Tank     | High DEF/HP operator              | Medium   |

### Pro Tip: SP Generation Focused

The slowed natural SP recovery demands an active playstyle. Build a team around operators who generate SP through attacking and using skills:

* • Multi-hit attackers (more hits = more SP)
* • Combo-skill specialists (combo abilities generate SP)
* • Physical/Heat operators (typically high attack speed)
* • Operators with SP-generating passives

## When to Farm Promotions

| Authority Level | Recommended Stage | Runs Per Day |
| --------------- | ----------------- | ------------ |
| 25-30           | Stage 1-2         | 2-3          |
| 30-40           | Stage 2-3         | 2-2          |
| 40-50           | Stage 3-4         | 1-2          |
| 50+             | Stage 4-5         | 1-2          |

## Common Mistakes & How to Avoid Them

### 1\. Running Stage 5 too early

Problem: Attempting Tacit Maelstrom at Authority 25-30\. **Fix: Progress naturally. Stay on Stage 1-2 until operators Level 30-40\. Stage 5 requires E2-E3 team.**

### 2\. Ignoring Set B options

Problem: Always choosing Set A when Set B might better suit your needs. **Fix: Check your Promotion Material inventory. Choose Set B if you need Intermediate materials for E2+.**

### 3\. Not building for SP generation

Problem: Using passive operators when natural SP recovery is very slow. **Fix: Prioritize multi-hit and combo-skill operators. Active playstyle required.**

### 4\. Being passive with SP

Problem: Playing like normal stages, not accounting for slowed natural SP recovery. **Fix: Be aggressive! Attack constantly and use skills. Passive play won't work.**

## Quick Reference Checklist

## Frequently Asked Questions

### How many stages are in Promotions Protocol Space?

Promotions Protocol Space has 5 stages: Tacit Brook (40), Tacit Canal (50), Tacit Mere (60), Tacit Undercurrent (70), and Tacit Maelstrom (80) Sanity costs.

### What rewards do Promotions Protocol stages provide?

Stages 1-2 drop Basic Promotion Materials. Stages 3-5 offer Set A (Basic) and Set B (Intermediate) Promotion Material options. Stage 5 Set B provides 14 Intermediate Promotion Materials.

### What is the SP mechanic in Promotions Protocol?

Natural SP recovery is much slower than normal. Skill-based SP recovery (from hitting enemies, combos) is greatly increased, requiring an active playstyle with multi-hit and combo-skill operators.

### When should I start farming Promotions Protocol?

Start around Authority Level 25+ with Stage 1-2 for E1 materials. Progress to Stage 3+ when operators reach Level 30-40 and are E1 promoted for Intermediate materials.

### Which operators work best in Promotions Protocol?

Multi-hit Physical/Heat operators and combo-skill specialists excel because they generate SP the fastest. Avoid passive operators who rely on natural SP recovery.