DG2: Defense Grid 2 lets you and one friend defend the same alien-threatened base in a two-player tower-defense campaign. You place weapons along enemy routes, manage a shared or divided resource pool, and try to keep the invaders from stealing the power cores at the center of each map. Online co-op and local play both support two people, with two different cooperative rule sets: one shares nearly every decision, while the other splits build spaces and adds a score rivalry.
This is a planning game more than a direct-action one. You choose a tower, place or upgrade it, and watch the next wave move through its firing range. When aliens steal a core, the run is not always over: the carrier has to travel back through your defenses, and a kill on that return route can send the core home. A leak can turn into a rescue, but every wave keeps moving while you decide what to build next.
One base, two kinds of teamwork
In Co-Op Doubles, both players work on the same map and share resources, score, build locations, and the defensive plan. You can both place towers on available build sites, rather than taking control of separate halves of a base. That makes every construction decision part of one common puzzle: a new tower can change where aliens travel, which weapons get time to fire, and how much of the shared budget remains for the next wave.
Coordinated Defense also asks two players to defend one base, but divides its tower locations between them. Each player has a separate resource pool and a set of places where they can build. The team still needs to stop the same invasion, yet the mode tracks each side’s contribution and can feel like a contest over who made the more effective placements. It is cooperation with a competitive edge, not the same fully shared setup as Doubles.
The third multiplayer mode, DG Fighter, is versus rather than co-op. Each player defends a parallel map; enemies destroyed on one side reappear on the other, stronger. If you want to build one shared defense, choose a co-op mode rather than Fighter. Coordinated Defense also includes a score comparison, so Doubles is the clearest option when you want every resource and build space to belong to both of you.
There are no character classes that assign one person to support or offense. Your responsibilities come from the ruleset and the map. In Doubles, a tower or upgrade is a joint investment; in Coordinated Defense, build areas and budgets are divided, while the base itself remains a shared objective. The difference is easy to understand before a match starts, and it gives two friends a choice between pooling their tools or comparing their separate contributions.
Towers shape the route, not just the damage
Aliens follow paths toward the cores or the exit, and maps offer different kinds of build sites. Some restrict towers to positions beside the road; others let you build on open areas that aliens must route around. In those places, tower force fields can lengthen or redirect a path. That extra travel gives your defenses more time to attack, and can send enemies past the same firing lanes more than once. A tower is therefore both a weapon and, on the right map, part of the maze.
The arsenal has distinct jobs. Gun towers provide steady fire, Cannons deliver heavy hits, Missiles attack from long range, and Inferno towers leave enemies burning as they pass. Tesla, Laser, Temporal, Boost, Concussion and Meteor towers add electrical damage, shield disruption, slowing, support effects or area attacks. The game gives you range rings and enemy information to help read these options, but the roster still asks you to learn which effects answer which threat. A shielded enemy, a fast carrier and a stealth unit do not all call for the same answer.
Upgrading changes a tower’s power and cost. The build menu uses tower levels, with stronger versions demanding more resources, and tower items can modify how a tower behaves for a mission. Your selected command-team AI also brings a special weapon. These choices add another layer to a map without turning either player into a fixed class: you both remain commanders choosing from the same defensive toolkit, with Doubles sharing its costs and Coordinated Defense giving each player a separate pool.
Resources arrive over time and through enemy kills. The score also reflects the state of your core stock, the resources you still hold and the towers you have invested in. Finishing a mission with more cores and spending fewer resources improves the medal you earn. That makes a clean defense more than a survival check: the game gives you a reason to revisit a map and find a more efficient arrangement together.
The tower rules do not stay identical across every challenge. Modifiers can restrict tower types or upgrades, change available resources or core behavior, alter pathing, or send stronger waves continuously. Doubles supports maps and applicable challenge modes, so the same pair can take a familiar layout with a different set of constraints. Instead of introducing a new character kit, these variants change what the shared defense is allowed to do.
A campaign built from changing maps
The story follows human colony defenders trying to stop an alien invasion, with mission dialogue from a cast of command AIs and human characters. The campaign is arranged around maps and waves rather than movement through a 3D world: enemies enter from marked routes, towers fire automatically, and the pressure comes from how each wave interacts with the layout. Maps can shift or add build sites, so a familiar tower plan may need to change when the battlefield changes around it.
The base campaign lists 21 dynamic maps, and optional Aftermath adds a further five story missions. Challenge rules, difficulty settings and medal goals give the maps more than one way to play. The game also includes a level editor and Steam Workshop support. If you want to play a user-made map in co-op, check that the selected map supports your chosen mode; the built-in campaign and supported challenges are reliable options to plan around.
The pace is deliberate. Towers do the shooting once placed, and much of the work happens between waves as you inspect routes, pick a build site and decide whether to upgrade or add coverage elsewhere. You can speed up the action, and each mission checkpoints as waves arrive, so a mistake does not always mean starting the entire map over. Still, the main loop remains defense planning followed by watching the result. A group looking for constant character movement or a quick shooter will find a different kind of session here.
The audiovisual style supports a science-fiction story without taking the camera away from the map. Alien waves, colored tower effects and command-team voices give each defense a sense of place, but the view is often zoomed out so you can read several routes and build sites at once. That broad view helps with planning; it also means some alien details are small amid the effects. The steady parade of waves and tower fire is the point, not a cinematic action sequence.
A pair can play online or share one computer
Online co-op is built for two players. You can invite a friend or search matchmaking for a selected map and mode. The same multiplayer menu also offers the versus mode, so check that you have chosen Doubles or Coordinated Defense if you want to defend together. Online play does not add a third or fourth slot: DG2 is a game for a pair, not a larger party looking for a full squad match.
Local co-op also supports two players on one computer. Both local players share the same screen, and the local mode uses two input schemes: one player can use mouse and keyboard while the other needs a gamepad. The game supports Xbox controllers, but the local setup calls for mouse plus gamepad, so do not count on a two-controller arrangement.
Choose a two-player online session or two-player local co-op on one PC; online and local players cannot be combined in one game.
Is DG2 right for your two-player night?
DG2 fits friends who enjoy comparing routes, tower coverage and resource choices over a run that gives them time to talk. Doubles keeps the economy and build locations shared, while Coordinated Defense creates a more divided partnership with a competitive score layer. A large campaign and rule modifiers give you reasons to return to a map, and the separate versus mode provides another way for two players to use the same tower-defense systems.
Its limits are just as clear. Only two people can play together, the local second player needs a gamepad, and the game stays within the tower-defense genre rather than turning into a direct-control battle. The tower roster and alien types take learning, and difficulty can climb sharply partway through the campaign. Challenge rules and medal goals invite repeat runs, but the core loop stays focused on arranging towers, reading routes and watching waves; groups looking for new mechanics or objectives each time may find it repetitive after the campaign.
If you and a friend want a two-player strategy game where a misplaced tower can change an alien route and a stolen core can still be recovered, DG2 gives you a clear shared objective. Doubles keeps your tools together; Coordinated Defense lets you work toward the same survival goal from separate build zones. That difference is the heart of its co-op: the same invasion, with a choice between pooling every decision and dividing the work.