Unit coherency in Warhammer 40,000 10th edition is one of the core rules that shapes how armies move, fight, and control the battlefield. Whether you are a beginner assembling your first squad or an experienced player refining competitive tactics, understanding unit coherency 40k 10th edition is essential. Coherency determines how models in a unit must be positioned in relation to one another, directly affecting movement, objective control, pile-ins, consolidations, and overall battlefield strategy. While the rule may sound simple at first glance, its impact on gameplay is significant and can influence both offensive and defensive decisions throughout a match.
What Is Unit Coherency in 40k 10th Edition?
In Warhammer 40,000 10th edition, unit coherency refers to the requirement that models within the same unit must remain within a specified distance of at least one other model from that unit. This ensures that squads move and operate as organized formations rather than scattered individuals. The rule reinforces the concept that units represent coordinated groups of warriors acting together on the battlefield.
Under 10th edition rules, the standard coherency requirement is that each model must be within 2 inches horizontally and 5 inches vertically of at least one other model in the same unit. This applies to most infantry, cavalry, and similar unit types. These measurements create flexibility while still preventing extreme spacing.
Why Unit Coherency Matters
Unit coherency 40k 10th edition is not just a technical rule; it shapes how you position models for tactical advantage. Maintaining proper spacing affects
- Board control and screening.
- Protection against blast weapons and area attacks.
- Efficient movement through terrain.
- Combat engagement range and pile-in moves.
- Objective holding capabilities.
If a unit fails to maintain coherency at the end of a move or turn, it may be forced to remove models until coherency is restored. This penalty makes proper positioning crucial during every phase of the game.
Coherency Rules for Different Unit Sizes
One important detail in unit coherency 40k 10th edition is how unit size affects positioning. Smaller units are easier to maintain, while larger squads require more attention to spacing.
Units of Two to Five Models
For units consisting of two to five models, each model must be within 2 inches of at least one other model in the unit. This allows flexible formations such as lines, arcs, or small clusters. Because fewer models are involved, maintaining coherency is relatively straightforward.
Units of Six or More Models
For larger units, the coherency rule becomes stricter. In units of six or more models, each model must be within 2 inches of at least two other models in the same unit. This prevents players from stretching large squads into long chains across the battlefield. Instead, it encourages tighter formations and more realistic group movement.
This rule significantly impacts horde-style armies that rely on large squads. Players must balance spreading out for board control with keeping enough proximity to satisfy the two-model requirement.
Movement Phase and Coherency
The movement phase is where unit coherency 40k 10th edition is tested most often. Every time a unit moves, advances, falls back, or charges, players must ensure that models end their move in legal coherency.
Common Movement Mistakes
Even experienced players can accidentally break coherency. Some common errors include
- Stretching models too far to reach an objective.
- Moving front-line models forward without adjusting rear models.
- Forgetting vertical distance when moving across terrain.
- Consolidating in combat without checking final spacing.
Careful measurement and planning are essential. Before finalizing a move, it is wise to check distances between multiple models rather than relying on visual estimation.
Coherency in the Fight Phase
Unit coherency 40k 10th edition also plays a role during the fight phase. When units pile in or consolidate after combat, models must end these moves in coherency. Because combat often causes units to shift positions rapidly, this is a frequent point of error.
For example, a model may pile in toward the closest enemy model, but if that move places it too far from friendly models, it can break coherency. Strategic combat positioning means thinking not only about maximizing attacks but also about maintaining formation integrity.
Tactical Uses of Coherency
Although unit coherency may seem restrictive, it can be used strategically to your advantage. Smart players leverage coherency rules to optimize battlefield control and durability.
Screening and Area Denial
By spreading models carefully within legal coherency limits, players can create effective screens that block enemy deep strikes or charges. Maintaining a 2-inch spacing between models allows coverage of larger areas while remaining compliant with rules.
Mitigating Blast Weapons
Blast weapons often become more powerful against larger units. By managing coherency and spacing, you can reduce clustering and limit the number of models affected by area-based attacks.
Objective Control
In 10th edition missions, holding objectives is central to victory. Unit coherency ensures that models remain connected while spreading onto objectives. Proper positioning allows a single unit to control space without risking forced model removal due to broken coherency.
Coherency and Terrain Interaction
Terrain introduces vertical measurement into unit coherency 40k 10th edition. Models must remain within 5 inches vertically of each other. This matters when climbing ruins, occupying multi-level buildings, or fighting across elevated platforms.
Vertical coherency adds depth to gameplay. Players can position models on different floors of terrain features, as long as vertical spacing does not exceed the allowed limit. This flexibility allows creative tactical positioning while maintaining rule compliance.
How 10th Edition Coherency Differs from Previous Editions
Compared to earlier editions, 10th edition streamlined many rules, including unit coherency. The fundamentals remain similar, but wording has been clarified for easier interpretation. The two-model requirement for larger units continues to prevent excessive conga line formations that once dominated certain competitive strategies.
This streamlined approach improves gameplay flow while preserving tactical depth. Players still need to think carefully about positioning, but the rules are more accessible for newcomers.
Tips for Maintaining Proper Coherency
Keeping unit coherency 40k 10th edition under control requires practice and attention. Some helpful tips include
- Move models in small groups rather than individually.
- Measure from multiple points before finishing movement.
- Keep central anchor models that others stay close to.
- Double-check spacing after pile-ins and consolidations.
- Avoid overextending toward distant objectives.
These habits reduce mistakes and help maintain consistent, legal formations throughout the game.
Unit coherency 40k 10th edition is a foundational rule that shapes movement, combat, and strategic positioning in Warhammer 40,000. By requiring models to remain within 2 inches horizontally and 5 inches vertically, and enforcing stricter requirements for larger units, the game maintains realistic formations and balanced tactics. Understanding these mechanics helps players avoid penalties and maximize efficiency on the battlefield.
Far from being a minor technicality, unit coherency influences nearly every phase of play. From screening enemy threats to managing combat positioning and securing objectives, proper spacing determines whether a unit functions smoothly or suffers costly losses. Mastering unit coherency in Warhammer 40,000 10th edition is therefore essential for players who want to improve their tactical awareness and overall performance in competitive and casual matches alike.