Glossary

Fortress glossary

A quick reference for the words you will see on the board, in battle and at HQ. Terms are grouped by topic; follow the linked guides for examples.

Board & battle

Fortress: your complete defense, made from four sectors and the towers that survive between waves.

Sector: one of the fortress’s four defensive sides, with its own merge board.

Build: the preparation phase. Choose a sector and spend limited moves arranging and merging its towers.

Swipe: a directional move that slides participating towers; equal tiers can merge when they meet.

Attack: the battle phase. Towers defend against the infected, and ready Tactical Support commands can be used.

Wave: a numbered incoming attack. The wave reached and the number of defenses actually played can differ.

Start Here → · Reading the Battlefield →

Towers & threats

Tier: a tower’s numbered merge level. Equal tiers merge into the next tier.

Tower 2: merge material. Tower 4 is the first active firing defense.

HP: a tower’s remaining health. A destroyed tower no longer contributes to your defense.

Coverage: the approaches your active defenses can reach. More tower value does not automatically mean better coverage.

Range: how far a tower’s attacks can reach.

Fire rate: how quickly a tower can fire.

JAMMED: a warning that a tower’s firing is being suppressed. Check the source of disruption.

Infected: the enemies threatening the fortress. Their attack behaviors and warnings differ.

Towers → · Zombie Field Guide →

Core & Cure Project

Core Merge: a limited-move opportunity that uses the marked fortress center as a shared merge workspace. Towers outside its boundary do not participate.

Center Assembly: a larger central workspace that may become available later. Read the preview and marked boundary for the current attempt.

Core partner: a matching tower that can combine toward the current Core target. A partner elsewhere in the fortress may be outside the active workspace.

Research Core: the marked physical tower carrying your research breakthrough. Its identity follows it when it moves or merges upward. Its destruction triggers Game Over, even if other towers remain.

Cure Project: the seven research milestones leading from the 2048 Prototype Core to the Final Cure.

Validation: the defense test that secures a research milestone. Creating the target Core and surviving its validation are separate achievements.

Core Defense: the defensive choice offered after a Core Merge window, before the incoming attack.

Journey: a campaign stage toward the next Cure milestone. Completing one does not necessarily complete the campaign.

Core Merge → · The Cure Project →

Build Tools

Build Up: raises an eligible living tower by one tier without spending a Build move. It is not a repair, cannot create a new highest tier, and cannot upgrade the tracked Core.

Undo: restores the most recent eligible Build swipe. It is a one-swipe correction, not a way to reverse battles, tool use or permanent rewards.

Hammer: removes an eligible non-Core tower to clear space. It cannot remove the tracked Research Core.

Tools are used during eligible Build windows. Follow their on-screen availability, target highlights and remaining charges.

Resources & Research

Scrap: the fortress’s run resource, used for repair and available preparation choices.

Research Samples: research gathered during a run, before it is settled into permanent progression.

Research Bank: banked Research used for lasting Lab upgrades. It is separate from the Samples still being gathered in a run.

Gold: a separate currency for eligible Shop and recharge options when available. It does not replace Scrap or Research.

Lab: the HQ destination for spending Research Bank on permanent upgrades.

Abilities & Tactical Support

Ability card: a temporary effect for the tower tier named on the card, used for its designated wave.

Tactical Support: commands you use during Attack to respond to a specific threat, when ready.

Convoy: armed trucks that sweep a sector. Your decision is when to call them.

Signal Flare: a placed beacon that diverts eligible infected for a short window.

Minefield: a trap placed at a marked perimeter socket; an approaching enemy triggers its local blast.

Strike Plane: a targeted battlefield strike. Nearby friendly towers can also take damage, so choose the impact carefully.

Perimeter socket: a marked placement point around the fortress used for a Minefield.

Cooldown: the wait before a used support can become ready again. Read the command’s availability and target requirements.

Ability Cards → · Tactical Support →

Saved progress & recovery

HQ: the hub for your active fortress, progression and preparation between gameplay sessions.

Continue: resumes your active saved fortress. Browsing a guide or Collection does not select an earlier board to restore.

Collection: the reference destination for discovered tower forms, Cure progress and campaign Records in the current development build.

Checkpoint: a saved recovery state. If a valid checkpoint is available, Game Over can offer a free restore to its displayed wave.

Records: read-only campaign history and personal progress. Records are not saved boards you can load.

Game Over: a failed defense caused by losing all firing defenses or the active Research Core. Available recovery choices are shown on that screen; Core loss cannot be bypassed with a paid or ad revival.

Common Questions → · Return to Start Here →

Development guide · Updated October 9, 2026. Describes the current development build. Availability, controls and balance may change before release.