Protocol Spaces Complete Guide
All 6 Protocol Spaces, Crisis Drills, Authority-based Progression, and Daily Sanity Budget
Last updated: 2026-02-09
Complete guide to all 6 Protocol Spaces in Arknights: Endfield including Operator EXP, Promotions, T-Creds, Skill Up, Weapon EXP, and Weapon Tune, plus Crisis Drills with authority-based progression and daily sanity budget recommendations.
* TL;DR - Key Points
- * 6 Protocol Spaces for progression materials (Operator EXP, Promotions, T-Creds, Skill Up, Weapon EXP, Weapon Tune)
- * Sanity costs: 40-80 per stage (5 stages each) - budget your daily 240+ Sanity
- * Best early game: Operator EXP Stage 1-2 (Derivative Memories/Trials) - most Sanity-efficient
- * Best mid game: Promotions Stage 2-3 (Tacit Canal/Mere) - balance promotion returns
- * Best late game: Skill Up Stage 4-5 (Echoes/Mirage of the Tower) - highest Skill mat density
- * Crisis Drills: 6 Hazardous Material sites (300 Oroberyl, 15 ESB, 1200 Op EXP total)
- * Unlock: Via Index menu after discovering in world
Contents
What Are Protocol Spaces?
Protocol Spaces are specialized instanced challenge modes in Arknights: Endfield that allow you to farm progression materials by spending Sanity. Each Protocol Space is a combat arena where you defeat waves of enemies to earn rewards.
How They Work
- 1. Locate in World - Discover Protocol Spaces throughout Talos-II (Valley Pass, The Hub, Valley IV, etc.)
- 2. Access via Index - After discovery, enter from the Index menu without traveling to location
- 3. Choose Stage - Each Protocol Space has 5 stages with increasing Sanity cost and rewards
- 4. Complete Stage - Clear combat waves to earn materials
- 5. Claim Rewards - Choose Set A or Set B at Sanity cost (failing or leaving does NOT cost Sanity)
Why Protocol Spaces Matter
- Resource Efficiency: Higher material density than open-world farming for some items
- Guaranteed Drops: No RNG compared to enemy drops in wild
- Progressive Unlock: Different spaces unlock as you progress through main story
- Daily Routine: Essential part of optimized daily Sanity budget
- Endgame Content: Stages 4-5 provide best material-to-Sanity ratios
The 6 Protocol Spaces Complete Overview
Operator Progression Protocol Spaces (4 Types)
| Space | Location | Purpose | Sanity Range |
|---|---|---|---|
| Operator EXP | Valley Pass | Combat Records, EXP Crystals | 40-80 |
| Promotions | The Hub | Promotion materials | 40-80 |
| T-Creds | Valley Pass, Valley IV | T-Credits (currency) | 40-80 |
| Skill Up | The Hub, Valley IV | Skill materials | 40-80 |
Weapon Progression Protocol Spaces (2 Types)
| Space | Location | Purpose | Special Mechanics | Sanity Range |
|---|---|---|---|---|
| Weapon EXP | The Hub | Weapon EXP materials | Lv 1-2: Arts Reactions bonus Lv 3+: DMG Reduction mechanics | 40-80 |
| Weapon Tune | The Hub | Weapon tune materials | Lv 1-2: Physical Statuses bonus Lv 3+: Vulnerability mechanics | 40-80 |
Crisis Drills (6 Hazardous Material Sites)
All 6 sites offer first clear rewards: 50 Oroberyl, 3 Emergency Sanity Boosters, 200 Operational EXP
Locations: Origin Lodespring (1), Power Plateau (1), Jingyu Valley (2), Wuling City (1), [Sixth site TBD]
Detailed Protocol Space Breakdowns
For detailed stage-by-stage walkthroughs, team compositions, and strategies, see the individual Protocol Space guides:
Crisis Drills
6 Hazardous Material sites scattered across Talos-II
First clear: 300 Oroberyl, 15 ESB, 1200 Op EXP total
View Crisis Drills Guide →When to Farm Each Protocol Space
| Authority Level | Protocol Spaces | Priority | Reasoning |
|---|---|---|---|
| 1-19 | None | Skip | Not unlocked yet, focus on main story |
| 20-25 | Operator EXP Stage 1-2 | Very High | Most Sanity-efficient operator leveling |
| 25-30 | Add Promotions Stage 1-2 | High | Need promotion materials for E1-E2 |
| 30-40 | Add Skill Up Stage 1-3, T-Creds Stage 1-2 | High | Skill leveling becomes priority |
| 40+ | All Protocol Spaces Stage 4-5 | High | Best material density, endgame gearing |
Pro Tip: Daily Sanity Budget Split
For 240 Sanity: Operator EXP Stage 1-2 (80-150), Promotions Stage 2-3 (50-120), Skill Up Stage 1-3 (40-120), Dungeon (110). Adjust based on needs.
Maximizing Protocol Space Efficiency
Sanity vs Material Value Analysis
Top Efficiency Stages:
- Operator EXP Stage 1 (Derivative Memories) - Early game leveling
- Operator EXP Stage 2 (Derivative Trials) - Good balance
- Promotions Stage 2-3 - Efficient promotion materials
- Skill Up Stage 4-5 - Highest skill material density
Set A vs Set B Strategy
When both Set A and Set B rewards are offered (Stage 3+), choose based on your current material inventory needs. Check what you're lacking most and choose the set that fills that gap.
Common Mistakes & How to Avoid Them
1. Running Stage 5 prematurely
Problem: Attempting Stage 5 with underpowered team wastes Sanity. Fix: Progress naturally. Stay on Stage 2-3 until clears are consistent.
2. Ignoring Set B options
Problem: Always choosing Set A when Set B might better suit your needs. Fix: Check your material inventory before choosing.
3. Farming wrong Protocol Space for progression
Problem: Grinding T-Creds when you need operator EXP. Fix: Match Protocol Space to your current progression priority.
4. Not using buffs/consumables
Problem: Attempting high-stage runs without buffs. Fix: Use healing/damage buffs from Depot for Stage 4-5 attempts.
5. Soloing Protocol Spaces
Problem: Bringing single operator when team synergy matters. Fix: Build balanced 4-operator team for each Protocol Space.
6. Forgetting Stage mechanics
Problem: Playing Stage 5 with Stage 1 mindset. Fix: Each stage has unique mechanics - read them before entering.
Quick Reference Checklist
Frequently Asked Questions
How do you unlock Protocol Spaces in Arknights: Endfield?
Discover Protocol Spaces in the world while exploring (Valley Pass, The Hub, Valley IV, etc.), then access them via the Index menu after discovery. Different spaces unlock at different Authority levels as you progress through main story.
What is the best Protocol Space for farming?
Operator EXP Stage 1-2 (Derivative Memories/Trials) offers the best Sanity efficiency for operator leveling in early game. Late game, Skill Up Stage 4-5 (Echoes/Mirage of the Tower) provides highest skill material density. Choose based on your current progression needs.
How much Sanity should I spend on Protocol Spaces daily?
For 240 daily Sanity, allocate 80-150 Sanity to Operator EXP Stage 1-2 (2-3 runs), 50-120 Sanity to Promotions Stage 2-3 (1-2 runs), and 40-120 Sanity to Skill Up Stage 1-3 (1-2 runs). Adjust based on your current needs and remaining Sanity.
Do Protocol Spaces cost Sanity if you fail?
No. Leaving or failing a Protocol Space does NOT consume Sanity. Only claiming the rewards costs Sanity. You can attempt a stage as many times as you want and pay the Sanity cost only when you successfully complete and claim rewards.
How do Crisis Drills differ from Protocol Spaces?
Crisis Drills are 6 Hazardous Material sites with one-time first clear rewards (50 Oroberyl, 3 ESB, 200 Op EXP each). Protocol Spaces are 6 resource farming spaces (Operator EXP, Promotions, etc.) you can run repeatedly for materials. Crisis Drills are combat challenges, Protocol Spaces are farming stages.