Delta Green
Delta Green is modern conspiracy horror about agents investigating the unnatural, burying the evidence, and watching the mission damage their sanity, relationships, and careers.
Modern conspiracy horror • Percentile skills, Bonds, and Sanity • 2-5 players + Handler • Strong for one-shots or campaigns • High-intensity adult play
Delta Green is one of the strongest fits on the site for groups that want investigation to feel like professional work instead of pulp adventuring. It is not the best choice for heroic monster hunters or tables that want horror to stay at a safe, cinematic distance. Delta Green works best when the group wants the case, the cover-up, and the personal fallout to matter equally.
What makes it distinctive is that the operation does not end when the threat is neutralized. The game keeps asking what the agents lied about, what evidence they destroyed, who they endangered, and what the mission cost them at home. That pressure is why Delta Green remains a benchmark for modern conspiracy horror.
What Delta Green is
Delta Green is Arc Dream Publishing's modern conspiracy-horror TTRPG about agents confronting the unnatural while hiding it from the rest of the world. The current standalone line casts the player characters as federal agents, soldiers, scientists, analysts, and civilians who become part of covert operations against Mythos threats, cult activity, impossible artifacts, and the bureaucratic damage those missions leave behind.
The setting descends from the original 1990s Delta Green material by Dennis Detwiller, Adam Scott Glancy, and John Scott Tynes. The current standalone rules line is credited to Shane Ivey, Dennis Detwiller, Christopher Gunning, and Greg Stolze, with Arc Dream expanding the line through campaigns, sourcebooks, and scenario collections rather than treating the core books as a closed product.
Publication history and editions
Delta Green began as a 1990s setting book for Call of Cthulhu, and Arc Dream's later The Conspiracy explicitly presents itself as an updated version of the original 1997 sourcebook. The standalone line took shape with the free Need to Know quickstart and the Agent's Handbook in 2016, then the Handler's Guide and the Delta Green: The Role-Playing Game slipcase set in 2018.
That matters because the current game is not a reboot that discarded its history. It is a standalone continuation that keeps the conspiracy's older material usable while shifting the emphasis toward post-9/11 paranoia, fractured institutions, and the schism between the Program and the Outlaws. Arc Dream's retailer listings show the line is still active in 2026, with recent releases such as The New Age in February 2026, Owlshead Mountain in April 2026, and Artifact Zero in May 2026, plus more material announced for later in the year.
What you need to play
The easiest on-ramp is Need to Know, which includes pregenerated agents and the starter operation "Last Things Last." For full play, most groups will want the Agent's Handbook, which is the player-facing rules volume, and a Handler will usually want the Handler's Guide for the setting history, threat material, and campaign tools.
If you already know you want the full game, the slipcase set is the cleanest core purchase. Arc Dream's official publications page also shows support for PDF, print, Roll20, and Foundry versions of the quickstart and core player book, which makes the line easier to stage for online play than many horror games with a similar tone.
Major campaigns, sourcebooks, and starting scenarios
Delta Green's support line is one of its major selling points. For new groups, Need to Know and "Last Things Last" are the obvious first stop, and Control Group is a strong second step if you want onboarding scenarios that introduce ordinary people to the setting before they become seasoned agents.
For campaign play, A Night at the Opera and Black Sites are practical scenario collections because they give a Handler operations that can be slotted into a longer campaign without requiring a giant metaplot commitment. The Complex and The Labyrinth are especially useful for groups that want more institutional texture, more agencies, and more human adversaries rather than just another monster file.
When a table wants a flagship long-form campaign, Impossible Landscapes is the line's most famous reality-bending horror campaign, while God's Teeth and Iconoclasts are better fits for groups that want emotionally punishing material or geopolitical pressure. None of those are ideal first books for a brand-new Handler, but they show how wide the line can stretch without losing its identity.
Digital tools and VTT support
Arc Dream's publications page lists official Roll20 and Foundry support for Need to Know and the Agent's Handbook, plus official digital releases for several scenarios. That is enough to make remote play straightforward without turning Delta Green into a map-first VTT game.
The important point is that Delta Green does not become a different experience online. The game still depends more on evidence, interviews, handouts, and pressure than on tactical positioning. A good digital setup helps with dossiers, props, and pacing; it does not replace the Handler's judgment.
Core rules and play structure
Delta Green uses a percentile roll-under system with skills that are easy to read at a glance. If a character has a skill at 60%, rolling 60 or lower is success. That familiar chassis gives the game a lower learning curve than many horror systems, especially for groups that already know Call of Cthulhu or other skill-driven games.
The real loop, though, is not about mastering a fancy dice engine. A typical operation moves through briefing, investigation, surveillance, interviews, data gathering, field decisions, and a crisis where the agents have to decide what counts as success. Delta Green is comfortable with combat, but it does not treat combat as the main reward cycle. Missions are won more often through preparation, interpretation, and ugly compromise than through balanced encounters.
Characters, Bonds, and advancement
Characters are defined by profession, practical skill spreads, and their connection to ordinary life. Delta Green agents can be competent from the start, but the game is not interested in superheroic scaling. It wants skilled people who are still vulnerable to panic, injury, bureaucracy, and bad judgment.
What separates Delta Green from many neighboring horror games is its use of Bonds and home scenes. Agents are tethered to family, friends, mentors, and routines that represent what remains of a normal life. Those bonds are not just flavor. They are part of how the game tracks stress, denial, and deterioration. Advancement exists, but it is incremental and overshadowed by the ways long operations damage careers, marriages, sanity, and trust.
Signature mechanics
The signature Delta Green mechanics are less flashy than they are corrosive. Sanity loss matters, but it matters because it spills into denial, adaptation, and damaged relationships. Bonds matter because they turn psychological damage into concrete personal fallout. Lethality rules matter because firefights are fast and frightening rather than tactical set pieces designed for fair fights.
Just as important is the way the game treats institutional access. Agents can lean on credentials, databases, agencies, and official procedure, but every use of authority creates exposure. Delta Green is at its best when the players realize that getting what they need legally, illegally, or quietly are all different kinds of risk.
What play feels like
At the table, Delta Green feels like a case file becoming a personal disaster. The early scenes often look procedural: witness interviews, dead drops, traffic cameras, crime scenes, paperwork, awkward interagency calls. The dread comes from realizing that the evidence does not fit the world and that every sensible response makes the agents more implicated.
That makes the tone different from many other Mythos games. Delta Green is rarely about wandering investigators following curiosity wherever it leads. It is about people with responsibilities trying to keep a lid on something that cannot be fully understood, often while pretending to their employer and their family that nothing is wrong.
Running Delta Green
Handler load is real, but it is specific. Delta Green does not demand giant tactical maps or elaborate encounter math. It demands strong clue structure, believable NPC motives, and confident pacing when a scene goes off-book. Published operations help a lot because the line is very good at teaching its own rhythm through examples.
The game also asks for tonal discipline. If a Handler treats every mission like a gunfight waiting to happen, Delta Green flattens out. The better approach is to let procedure, secrecy, and moral compromise carry the pressure until the violence feels like a failure state or a desperate necessity.
Campaign fit
Delta Green is good at one-shots and stronger in campaigns. One-shots work because the premise is immediately legible: the agents receive a briefing, investigate the impossible, and contain the fallout. Campaigns work even better because the accumulated damage is one of the line's central pleasures.
A longer campaign lets recurring contacts, damaged bonds, bureaucratic enemies, and unresolved operations start haunting the group. The game does not need a giant world-saving arc to feel substantial. It needs missions that leave residue.
Reception and awards
Reception has been exceptionally strong for years. Arc Dream's own FAQ says the line has won three Origins Awards and 14 ENnie Awards, including a gold ENnie for Need to Know as Best Free Game in 2016, a silver ENnie for the Agent's Handbook in 2016, and gold ENnies for Delta Green: The Role-Playing Game in Best Rules and Best Production Values in 2018.
Critical response lines up with that reputation. RPGnet's review of the Agent's Handbook framed the game as a successful standalone continuation of the old setting, while its review of the Handler's Guide called the book an essential, genre-updating resource. Rascal's 2024 commentary on the line focused on how Delta Green adventures create an atmosphere of bureaucratic control that makes the horror cut deeper. The broad pattern is consistent: praise for tone, setting depth, and scenario support, with caveats that the line is emotionally heavy, lore-dense, and uninterested in easy victories.
Where Delta Green is strongest
- It is one of the clearest modern cosmic-horror recommendations on the site, because agencies, coverups, and normal life are active parts of play.
- Its support line is unusually deep, so a new Handler can start small and still have a long runway into campaigns and specialist sourcebooks.
- Bonds and home scenes turn horror consequences into personal consequences, which gives campaigns a very different shape from clue-only investigation games.
- The percentile rules stay readable even when the scenarios become psychologically or morally complicated.
Where it can frustrate groups
- It is a poor fit for tables that want horror as cathartic action or monster-of-the-week heroics.
- The tone can become draining if the group does not want repeated exposure to secrecy, compromise, and loss.
- Handlers still need to manage clue flow and scenario pressure carefully; the rules do not solve investigation design for you the way Trail of Cthulhu tries to.
- Combat is dangerous and memorable, but not deep in the miniatures-game sense. Groups chasing crunchy tactical firefights may want something else.
Content and safety notes
Delta Green frequently engages with adult material: institutional violence, coercion, corruption, addiction, mental deterioration, self-harm, abuse of authority, body horror, cult violence, and the destruction of family or career stability. Some famous scenarios also involve child endangerment, sexual violence implications, or intensely cruel emotional material.
That does not make the game unplayable. It does mean the table should establish boundaries early, revisit them during longer arcs, and treat campaign selection as a safety decision as much as a taste decision.
Best starting path
Start with Need to Know and run "Last Things Last." If your table responds well, move to the Agent's Handbook and pick a short operation from A Night at the Opera or Black Sites. Add the Handler's Guide once you know you want the broader setting, the Program versus Outlaws split, and the deeper campaign toolset.
Save Impossible Landscapes, God's Teeth, and similarly punishing campaigns for a group that already knows it wants Delta Green specifically, not just "a horror game." The line rewards commitment, but it is better when that commitment is informed.
Research notes
Last checked: 2026-07-02.
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