Board Shaping — Push, Kill Zones, and Explore Lockout
Every Spirit Island turn eventually reduces to one question: where do the pieces go? Push them toward the coast, or into a kill zone? Leave this land at 2 Invaders, or pull a fourth one in and light it up? The answers depend on three decisions that compound across turns — get any of them wrong and the board shape collapses faster than your Fear track can generate burst.
This chapter is the decision framework. It assumes you’ve read Adjacency & Range and Terrain; those cover what moves where, not when you should want it to.
Why board-shaping matters
Fear generation gets the headlines, but board state is the scoreboard for most games. A board with 4 Blight and 12 Invaders on T5 is losing regardless of fear count; a board with 0 Blight and a known-dying ravage lane is winning regardless of whether Terror 2 has hit. Every push, every gather, every Remove/Destroy choice is shaping that state.
The critical property of board state: it compounds. A Town you left alive on T3 is a City that drops two Invaders into an adjacent land on T6. A coastal land you diluted into has two more Explorers by T5 because the Ocean never stops seeding. Decisions made at mid-game get amortized across every remaining turn.
The three decisions inside every push
When a power offers “push up to N pieces,” you’re actually making three decisions in sequence:
- Direction. Coastal, interior, into a land with Dahan, into a land adjacent to your planned kill zone?
- Density. Concentrate pieces into a single land (for an AOE) or dilute them so no land hits ravage critical mass?
- Durability. Will the push put pieces somewhere they’ll stay dead after the kill, or somewhere Explore will re-seed them next matching draw?
Good players juggle all three implicitly. New players usually fixate on #1 and treat #2 and #3 as rounding errors — which is why T6 always looks worse than T3 did.
Coast always explores — the statistical floor
Add an Explorer to every land of the shown type which either:
- Contains a Town or City; or
- Is adjacent to a Town, City, or Ocean.
No matter how many sources are in or adjacent to an Explored land, you only add one Explorer.
Source: see data/references/rules/explore-phase.md for the verbatim rule and Wiki revision ID.
The “adjacent to Ocean” clause is the fault line every board-shaping decision runs along. Every coastal land is a permanent Explore source. You cannot Explore-lock the coast short of removing it from the map entirely (which only a few scenario/power effects can do). An interior land, by contrast, can go Explore-dead: if neither the land itself nor any of its adjacent lands contains a Town or City, a matching Explore card adds nothing.
The statistical weight
Each Invader Deck card is one of four terrains (or a Stage-specific terrain pair). On any given Explore:
- Coastal lands matching the terrain: every single one gets an Explorer. No exceptions.
- Interior lands matching the terrain: only the ones still linked to a Town/City chain get an Explorer.
On a standard 8-land board, roughly half the lands are coastal. So at least half of every matching Explore draw is guaranteed to land on the coast. Clearing coastal Invaders buys you one turn of relief; Explore refills them on the next matching card. Clearing interior Invaders — and the building chain feeding them — buys you permanent relief until Build or an Event reseeds.
This is why experienced players prioritize clearing interior Towns: the kill is durable. A coastal Town killed on T4 becomes an Explorer on T5 (matching terrain) and a Town again on T7 Build. An interior Town killed on T4, with its adjacent chain also broken, stays dead.
Before you clear an interior land, check the 4–6 lands adjacent to it. If none of them contains a Town/City either, your clear just Explore-locked a pocket of the island. That’s a 3-turn head start on Blight.
Concentrate vs. dilute — decision framework
Given the push you’re about to make, should you pack Invaders into one land (concentrate) or spread them across multiple lands (dilute)?
| Factor | Favors concentrate (kill zone) | Favors dilute (buy turns) |
|---|---|---|
| AOE kill power in hand / offering | Yes — Pyroclastic, Terrifying Nightmares, Sleep, Vengeance, Vanish Softly | No — can’t punish the pile |
| Fear deck proximity to Terror 2 / 3 | Threshold is 1–2 cards away; mass-kill flips the track | Far from threshold; Fear won’t spike anyway |
| Ravage timing | Kill resolves before Ravage (Fast AOE, or Slow that beats Ravage) | Ravage imminent — concentration = mass Blight |
| Blight pool health | Healthy — can absorb one bad Ravage if the kill misses | Near cascade — dilute to buy turns |
| Dahan in target land | Empty land or invader-only land | Dahan present — keep them alive, spread Invaders away |
| Adversary ramp | Escalation-lite (base England L1–3) | Escalation-heavy (Prussia Town→City, Sweden Build spam) |
| Coastal stakes | Interior kill zone — coast stays clean | Coast has upgrades already — don’t feed it more |
| Explore durability | Interior target — kill is durable if chain also breaks | Coastal target — kill will re-seed anyway |
No single row wins; you’re summing the column. Concentration is a big-swing play with a tight window; dilution is a steady-state play that costs you Fear.
Pushing three Invaders into a coastal land on T4 because you had a Slow AOE queued — then the AOE turns out to be conditional on an element you didn’t hit, the Ravage fires through 4 Invaders, and the land goes 2-Blight. The concentration was correct conditional on the kill; without it, you would have been better off diluting and taking the smaller Ravage.
Adversary riders
Ramp shape changes which of the two defaults is correct. These ride on top of the table above:
- England (L3+): Stage III adds Cities to coastal lands on Build. Diluting into the coast feeds future Cities. Prefer interior kill zones even when AOE is shaky. See England chapter.
- Brandenburg-Prussia: Sands attracts building upgrades; piling Invaders in Sands is a trap unless the kill is locked the same turn. See Brandenburg-Prussia chapter.
- Sweden: Build-heavy; concentration lets a single Build/Ravage cycle compound. Dilute by default unless the kill is fast.
- France (Plantation Colony, B&C): Dahan attract Invaders. Push Invaders away from Dahan lands; concentrate in Dahan-empty lands. See France Plantation chapter.
- Scotland / Russia:
[VERIFY — adversary-specific ramp riders pending per-chapter review].
Spirit-archetype riders
Your spirit’s native toolkit biases the default:
- Push / move-heavy (Keeper, Finder, Wind, River): dilute by default. Your offense is geography, not damage. Kill zones only when a teammate is providing the AOE.
- Damage-heavy (Fire, Wildfire, Serpent, Volcano, Lightning): concentrate by default. Your kit is built for kill zones. Dilution leaves power on the table.
- Isolate-heavy (Shadows, Serpent): concentrate and isolate. A kill zone you can Isolate stops reinforcements for the turn it takes to light it up.
- Defense-heavy (Stone, Mist, Vital Strength): dilute by default. Your kit blunts Ravage; you don’t need to prevent the Ravage, you need to survive it.
- Fear farmers (Bringer, Shadows, Vengeance, Wandering Voice): concentrate in lands where the AOE will generate fear-per-kill, but dilute on off-turns to keep the board stable for long enough to finish the fear deck.
Worked example — T4 vs. Brandenburg-Prussia L5
Mid-game, 2-spirit: River Surges in Sunlight + Sharp Fangs Behind the Leaves. Your board has three threats:
- Interior Jungle at 2 Towns (adjacent chain: one more Town two lands over).
- Coastal Sands at 1 City + 2 Explorers.
- Interior Mountain at 1 Town (no adjacent Town/City chain).
Ravage Card revealed: Jungle. Fangs has Devouring Teeth queued (Slow, destroys 2 Invaders in a Jungle/Mountain). River has Wash Away prepared with Push-4.
Decision tree:
- Concentrate into the Jungle: Push the Sands Explorers inland, light up Devouring Teeth for 2 kills. Kills a Town but leaves the other Town and the City. Next turn’s Ravage still hits coastal Sands with a City.
- Dilute from the Jungle: Push the Jungle Towns into Mountain (Explore-dead) and Sands (coast, stays live). Devouring Teeth loses a target; you’ve traded 2 kills for durability on the Mountain push.
The Prussia rider says “Sands concentration = trap without locked kill.” You don’t have a Sands kill. Dilute the Jungle Towns: 1 into Mountain (durable), 1 into Sands (accepting the coast-always-explores cost). Use Devouring Teeth on the remaining Jungle Town; you still get 1 Invader cleared durably, and the Mountain land is now Explore-locked.
Common mistakes
- Diluting into a coastal land that already has 2+ buildings. You’re adding pieces to a land that Build will escalate anyway. Push-to-coast only works when the coastal land is low-density.
- Concentrating without AOE online. “I’ll deal with it next turn” is how kill zones become Blight sources. Don’t pile pieces you can’t punish.
- Ignoring Explore-lockout when clearing interior Towns. If you clear a Town and leave an adjacent Town alive, the land is not Explore-locked — it still seeds from the neighbor. Full lockout requires clearing the whole adjacent chain.
Further reading
- Adjacency & Range — what “adjacent” means mechanically.
- Terrain — terrain scarcity shapes which lands are candidates for kill zones.
- Dahan — Dahan presence flips the concentrate/dilute default.
- The Fear Track — kill zones are fear-burst plays; dilution is fear-slow.
- The Blight Track — Blight health gates concentration aggression.
- Combos — Terrain Control — specific power combinations that exploit Explore-lockout.
- Explore-phase rule reference — verbatim Wiki text + adjacency clarifications.