Contingency Contract: Indigo Experimental Operation is a new high-difficulty challenge event arriving in Arknights: Endfield Version 1.6, Sanctuary of Ink, on November 5, 2026.

The event lets players customize battle difficulty through selectable Test Criteria, earn exclusive rewards, and challenge increasingly demanding enemy encounters.

This Arknights Endfield Contingency Contract Indigo Indigo guide covers gameplay rules, recommended risk selections, team compositions, sharing codes, combat strategies, and shop priorities.

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Indigo Experimental Operation Event Overview

Contingency Contract is a free challenge mode where players select difficulty modifiers called Test Criteria.

Each criterion changes battle conditions, such as increasing enemy strength, restricting operator abilities, or modifying combat mechanics.

Test Criteria have difficulty levels ranging from 1 to 3. Their combined values determine the Total Test Criteria score.

Reaching higher scores unlocks additional challenges, while completing event missions rewards players with currency that can be exchanged for items.

Contingency Contract Indigo Rewards

Players earn Vitrified Indigo by completing contract missions and combat challenges. This currency can be exchanged for valuable resources in the Secret Sanctuary.

Completing every possible high-difficulty challenge is not necessary for players who primarily want progression rewards. Focus on accessible missions and gradually increase your score.

Best Difficulty and Test Criteria Selection

The most effective strategy is selecting criteria that have minimal impact on your main team's combat mechanics.

For beginners, start with low-risk combinations to understand enemy patterns.

Intermediate players can gradually approach a Total Test Criteria score of 20, adjusting individual modifiers when necessary.

Experienced players may pursue scores of 30 or higher, although these attempts demand stronger equipment and more precise execution.

Avoid combining multiple restrictions that weaken your team's primary damage source.

Contingency Contract Indigo Sharing Codes

The event supports importing and sharing Test Criteria combinations, allowing players to reproduce another player's modifier setup.

One Test Criteria combination shared by the Indigo Experimental Operation community is:

Import it through the event's Test Criteria interface and review the selected modifiers before attempting the challenge.

Remember that sharing codes reproduce criteria selections, not team equipment or combat execution. A successful setup for one player may require adjustments for another.

Recommended Teams for Indigo Experimental Operation

Reliable status application and controlled damage rotations are particularly useful in this event.

Cryo Burst Team

Last Rite serves as the primary damage dealer, supported by Xaihi, Tangtang, and Arcane.

This composition appeared in the Version 1.6 demonstration of the Combo Lock modifier.

Coordinate Combo Skills to maximize burst damage before the temporary restriction activates.

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Physical Team

The Endministrator and Chen Qianyu provide Physical damage and Vulnerability interactions, while Pogranichnik supports the team's offensive rotation.

Ardelia contributes healing and additional support.

This is a flexible alternative for players with developed Physical operators, though its effectiveness depends on the selected criteria.

Practical Combat Tips

Before starting a challenge, check enemy information and confirm that your team can handle the selected restrictions.

Prioritize dangerous enemies: Defeat ranged attackers and enemies with disruptive abilities before concentrating on remaining targets.

Control your SP usage: Avoid spending every Battle Skill immediately, especially when using Ambient: Silence.

Save important Ultimates: Reserve high-damage abilities for dangerous enemy groups or bosses instead of activating them as soon as they become available.

Adjust one criterion at a time: If you repeatedly fail with a particular combination, remove the modifier that most negatively affects your team's performance.

Since a failed run must be restarted, consistent survival is usually more valuable than attempting an unnecessarily difficult setup.

Secret Sanctuary Shop Exchange Priority

Spend Vitrified Indigo according to your immediate progression needs.

Oroberyl is the recommended first purchase because of its value for character recruitment.

Progression selection crates are useful for strengthening operators and preparing for future challenges.

Players collecting limited event cosmetics should also reserve enough currency before the shop closes.

Unused Vitrified Indigo will be cleared when the Secret Sanctuary closes, so remember to exchange your remaining currency.

Final Thoughts

Contingency Contract: Indigo Experimental Operation rewards thoughtful Test Criteria selection, reliable team combinations, and careful combat execution.

Start with manageable difficulty, gradually increase your score, and prioritize valuable rewards before challenging higher-risk setups.

With OSLink, players can also remotely access the PC version of Arknights: Endfield from their phones, making factory management, resource collection, and routine gameplay more convenient between challenging combat sessions.