This guide lists campaign structure and progression rather than giving a complete tower placement solution for every map. Challenge modes can change the rules on a familiar stage, so a campaign victory does not mean every challenge variant is cleared.
Fast answer
The answer before the background
The story route starts with the prologue, then runs through 20 numbered missions divided among five chapters: Threshold through Suspension in Chapter 1, Overlook through Split Decision in Chapter 2, Boiling Point through Sandstorm in Chapter 3, Incursion through Refuge in Chapter 4, and Double Take through Backlash in Chapter 5. Aftermath adds five more missions after Chapter 5. Waves are fixed per stage but are not uniform: verified listings show 20-, 25-, and 30-wave maps. Level 7 is Split Decision, while level 12 is Incursion. Custom maps are made and distributed separately through DGArchitect and the Steam Workshop.
Campaign overview
How the story stages are organized
The campaign is a sequence of tower-defense missions grouped into chapters. The official game help describes chapters as story sections that generally focus on a colony planet, while challenge modes reuse campaign maps with altered rules. That means the map name, mission number, and challenge rules are separate pieces of information.
The original campaign is best counted as 21 stages: a prologue followed by missions 1 through 20. The newer Aftermath content adds five advanced missions, bringing the full listed total to 26 when that expansion is included. The Nintendo Switch store page explicitly describes the package as a 26-mission campaign with a five-mission Aftermath chapter.
- Original story route: Prologue plus 20 numbered missions.
- Original chapters: five.
- Aftermath: five additional missions after Chapter 5.
- A medal is awarded according to cores saved and resources used, so finishing a stage and earning its best medal are different goals.
| Section | Stages | Mission numbers |
|---|---|---|
| Prologue | Prologue | Unnumbered |
| Chapter 1 | Threshold; Supply and Demand; Suspension | 1–3 |
| Chapter 2 | Overlook; Barrage; Rapid Collapse; Split Decision | 4–7 |
| Chapter 3 | Boiling Point; Precipice; Breach; Sandstorm | 8–11 |
| Chapter 4 | Incursion; Deep End; Surface Tension; Refuge | 12–15 |
| Chapter 5 | Double Take; Scarce Resources; Checks and Balances; Out of Control; Backlash | 16–20 |
| Aftermath | Tall Order; Out of Turn; Taking Charge; Poor Visibility; Damage Control | 21–25 after the prologue numbering |
Some databases count the prologue separately, while others present the campaign as 21 stages before Aftermath. Use the chapter and mission names in the table when a guide or achievement description uses a different numbering convention.
Mission route
Where level 7 and level 12 fit
Level 7 is Split Decision, the final mission of Chapter 2 in the commonly used numbered campaign list. Its defining progression problem is simultaneous pressure from two entrances, so a single central kill zone is less reliable than two lines of defense. Keep both routes active and avoid spending all resources on one side before the other has stabilized.
Level 12 is Incursion, the opening mission of Chapter 4. Community walkthroughs list it as a 30-wave stage with multiple entry points and a later threat arriving from behind. Treat it as a chapter transition: the map expects stronger economy management, more deliberate path control, and a reserve for late waves rather than an all-in opening build.
For either stage, restart early if the first few waves force you to sell repeatedly. Rebuilding costs time and usually leaves the next wave weaker. A cleaner approach is to place a modest first line, identify which route is doing the most damage, and upgrade that line before filling every available platform.
- For Split Decision, plan for two active lanes and check both entrances before each upgrade.
- For Incursion, leave resources for the late sequence instead of spending everything on the first visible approach.
- Use the wave timer to reposition or upgrade between attacks; do not wait until a core is already under attack.
- If the objective is a medal rather than simple completion, compare the score target after learning the map’s route.
| Search term | Verified match | Practical implication |
|---|---|---|
| Level 7 | Split Decision | Final Chapter 2 mission; two-entry pressure is the key map concern. |
| Level 12 | Incursion | First Chapter 4 mission; expect a longer, more demanding wave sequence. |
| Chapter 5 end | Backlash | Completing the original route places Aftermath immediately to the right when installed. |
Tower order and exact placement are recommendations, not mandatory solutions. The game’s flexible placement system allows several successful layouts, and the best choice changes with difficulty, augmentations, and selected AI.
Waves and gates
How wave progression works
Each stage has a predetermined invasion sequence, but the number of waves depends on the map. The verified campaign references show a 20-wave mission in Overlook, 25 waves in Sandstorm, and 30 waves in many later or more demanding missions. Do not assume that every stage has 30 waves or that the final wave uses the same enemy mix as the preceding one.
Resources arrive steadily during waves, with the official manual noting that the final wave is an exception to the normal per-wave resource flow. This makes the last approach a poor time to spend every reserve on a new tower unless that purchase directly prevents a core loss.
Story progression is the main gate: finish the available mission sequence to move through the chapters. Aftermath is a separate content gate. On Steam, the developer says to install the expansion and use the chapter arrow to the right of Chapter 5. The Switch product page includes the extra chapter in its advertised package. Other platforms or editions may expose different DLC menus, so check the store version rather than assuming every release contains it.
- Read the stage’s wave count before choosing an economy plan.
- Treat the last wave as a special case because normal resource timing may not apply.
- Expect chapter progression to unlock the next story section rather than every map at once.
- If Aftermath is missing, verify ownership, installation, and platform support before replaying Chapter 5.
| Wave pattern | What it usually means | Safe response |
|---|---|---|
| 20 waves | Shorter early or mid-campaign map | Prioritize a compact, upgraded core defense instead of excessive expansion. |
| 25 waves | Intermediate or specialist layout | Reserve money for the final third, where enemy mixes often become less forgiving. |
| 30 waves | Longer later-stage defense | Build a scalable route, upgrade key towers, and keep a response fund for late threats. |
The wave counts are verified examples from stage listings. The economy advice is a practical recommendation based on those lengths and the manual’s resource rules, not an official requirement.
Custom content
Custom levels versus campaign stages
Custom content is separate from the numbered story route. Defense Grid 2 includes DGArchitect, the game’s level-creation tool, and Steam Workshop support for submitting community-made maps. Workshop items are curated: uploading a map does not guarantee that it immediately appears as a playable in-game purchase or unlock.
On Steam, the developer also points players toward free community maps outside the standard store flow. These maps can have different layouts, wave scripts, objectives, or balance from the official campaign, so do not use a custom map’s behavior to infer how a numbered stage works.
To try custom content, open the game’s Workshop or custom-level area, review the map description and mode, then confirm whether it is free, accepted, purchased, or otherwise unlocked. Keep campaign saves and custom-map expectations separate, especially when following a guide written for an older build.
- Use the campaign menu for official story missions and challenge variants.
- Use DGArchitect or Workshop tools for community-created stages.
- Check platform availability before expecting Steam Workshop features elsewhere.
- Treat custom wave counts and balance as map-specific unless the creator documents them.
| Content type | Where it belongs | Progression effect |
|---|---|---|
| Story mission | Campaign menu | Advances the main chapter route. |
| Challenge mode | A campaign map with changed rules | Adds replay goals; it does not create a new story chapter. |
| Custom level | DGArchitect, Workshop, or approved community distribution | Normally separate from the official campaign progression. |
The strongest verification for custom maps comes from the Steam version. The official Steam Workshop documentation describes the publishing and curation system; it should not be treated as proof that identical tools exist on every console edition.
FAQ
Common questions
How many stages are in the original campaign?
Count the prologue plus 20 numbered missions for 21 original campaign stages. Some references call this a 20-mission campaign because they exclude the prologue from the numbered total.
Does Aftermath continue after the main story?
Yes. Aftermath adds five missions that continue after Chapter 5. On Steam, the developer says the added chapter appears to the right of Chapter 5 after the expansion is installed. The Switch store listing includes that five-mission chapter in its advertised 26-mission package.
What is Defense Grid 2 level 7?
Level 7 is Split Decision in the standard numbered campaign list. It closes Chapter 2 and requires attention to two active entry routes.
What is Defense Grid 2 level 12?
Level 12 is Incursion, the first mission of Chapter 4. Listings give it a 30-wave sequence, and walkthrough references emphasize its multiple entry points and later pressure from behind.
Are custom levels part of the story progression?
No. Custom maps are created and distributed separately through DGArchitect and, most clearly on Steam, the Workshop system. They can be excellent additional content, but their wave scripts and unlock rules are not part of the official campaign route.
Sources
What we checked
Official listings establish current availability and product facts. Community pages are used for mechanics and build history, then labeled separately.
- OfficialOfficial Xbox game help manual: campaign, chapters, waves, medals, and challenge modes
- OfficialOfficial Nintendo Switch product page: 26-mission campaign and Aftermath
- OfficialOfficial Steam product page: campaign, level tools, and Aftermath listing
- OfficialOfficial Steam announcements: Aftermath placement and custom-map information
- CommunityCommunity mission index: chapter and stage names, including Aftermath
- ReferenceCommunity level listings: numbered campaign order