- Serious Sam The Third Encounter storyline continues directly after The Second Encounter — not a prequel or spinoff.
- Sam Stone remains the hero hunting Mental's forces across new alien worlds.
- The game is in early development; full plot details, levels, and endings are still unannounced.
- Series lore centers on the ancient Sirian civilization and Mental's galactic invasion.
- All confirmed story facts below come from the official Steam listing.
Storyline Overview: What Is Confirmed So Far
The Serious Sam The Third Encounter storyline picks up where The Second Encounter left off, continuing Sam "Serious" Stone's one-man war against the alien overlord Mental. According to the official Steam store page, developed by Croteam and published by Devolver Digital, the game is a direct sequel — not a reboot, prequel, or side story. Sam will fight through new alien worlds rather than retracing Earth-based battlefields from earlier entries.
Because the project is still in early development with a TBA release date, many narrative specifics — level names, cutscene details, supporting characters, and the ending — have not been published. This guide separates confirmed facts from series context so you can follow the story without relying on rumors.
| Story Element | Confirmed Status | Source |
|---|---|---|
| Direct sequel to The Second Encounter | Confirmed | Steam listing |
| Sam Stone as protagonist | Confirmed (series core) | Steam listing |
| New alien worlds to explore | Confirmed | Steam listing |
| Mental as the antagonist | Confirmed (series core) | Steam listing |
| Specific plot beats and ending | Not yet announced | Awaiting official update |
| Campaign length and level count | Not yet announced | Awaiting official update |
The game is unreleased. Any website claiming to reveal full mission lists, boss orders, or the ending of The Third Encounter is publishing speculation. Treat only the Steam listing and Croteam's official channels as story canon.
Series Timeline: Where The Third Encounter Fits
To understand the Serious Sam The Third Encounter storyline, you need the backbone of the series timeline. The classic saga follows Sam Stone, a captain sent back in time to ancient Egypt, where he uncovers Sirian technology while Mental's armies pour through time and space behind him.
| Series Entry | Story Role | Key Events |
|---|---|---|
| The First Encounter | Beginning of the campaign | Sam awakens in Egypt, uncovers Sirian ruins, fights Ugh-Zan |
| The Second Encounter | Immediate continuation | Sam pursues the Holy Grail across Mesoamerica, Babylon, and medieval Europe |
| The Third Encounter | Upcoming sequel | Continues directly from The Second Encounter, new alien worlds |
| Serious Sam 3: BFE | Prequel-era entry | Sam's earlier battles in a near-future Egypt invasion |
Think of the numbered Encounters as one continuous chase: each ends with Sam one step closer to Mental, and The Third Encounter is positioned as the next leg of that pursuit rather than a fresh starting point.
Core Lore: Sam, Mental, and the Sirians
The series' mythology is simple but effective, and it will almost certainly anchor the Serious Sam The Third Encounter storyline.
Sam Stone
- Humanity's last hope
- Time-traveling super-soldier
- Sardonic one-liners against Mental's taunts
- Carries the fight off-world in this sequel
Mental
- Ancient galactic destroyer
- Commands endless alien hordes
- Taunts Sam directly through the campaign
- Ultimate target of every Encounter
Sirian Civilization
- Extinct advanced alien race
- Left ships, portals, and ruins behind
- Their technology enables Sam's journeys
- Key to reaching Mental's domain
The Second Encounter ended with Sam hijacking a Sirian spacecraft and setting course deeper into Mental's territory. That cliffhanger is the natural launch point for this sequel: Sam leaving Earth's historical battlefields behind and carrying the war into alien worlds — exactly what the Steam description promises.
How to Catch Up on the Story Before Release
Follow these steps to be fully prepared when the Serious Sam The Third Encounter storyline drops.
Play The First Encounter
Experience Sam's awakening in ancient Egypt and the first battles against Mental's hordes. This entry establishes Sam, Mental, and the Sirian backstory.
Finish The Second Encounter
Complete the Grail chase through Mesoamerica, Babylon, and medieval Europe, ending with the Sirian spacecraft departure — the direct setup for this sequel.
Review Sirian Lore
Study the Sirian civilization's ruins and technology across both Encounters; their artifacts are the series' main plot engine and will likely matter again.
Track Official Channels
Follow the Steam page and Croteam for trailers and story reveals as development progresses.
Wishlist and Wait for Story Drops
Add the game to your Steam wishlist so release news, trailers, and story details arrive the moment Croteam publishes them.
Story Readiness Checklist:
- Complete The First Encounter campaign
- Complete The Second Encounter campaign
- Review the Sirian civilization lore
- Watch every official trailer on release
- Wishlist the game on Steam
The Steam listing confirms single-player, online co-op, and shared/split-screen co-op. Playing the campaign with friends does not change the storyline — the whole squad experiences Sam's story together.
Story Expectations vs. Rumors
| Expectation | Likelihood | Reason |
|---|---|---|
| Story continues in space / alien worlds | Very likely | Steam description confirms new alien worlds |
| Sam vs. Mental as central conflict | Very likely | Core of every mainline entry |
| Return of classic enemies (Kleers, Gnaars) | Likely | Series staple hordes appear in all entries |
| A final confrontation with Mental | Possible | Long-teased endpoint of the saga |
| Detailed rumor-based mission lists | Unverified | No official source; treat as fan speculation |
Every numbered Encounter has advanced Sam one step closer to Mental without a final resolution. Whether The Third Encounter delivers that confrontation is the biggest open story question — and Croteam has not answered it yet.
Storyline FAQ
Q: Is Serious Sam: The Third Encounter a direct sequel to The Second Encounter?
Yes. The official Steam listing confirms the game continues directly from The Second Encounter. It is not a prequel, reboot, or spinoff, making the Serious Sam The Third Encounter storyline the next chapter of the classic saga.
Q: Where does the Serious Sam The Third Encounter storyline take place?
The Steam page confirms Sam will explore new alien worlds, moving the campaign beyond the historical Earth settings of the first two Encounters. Specific planets and level names have not been announced.
Q: Do I need to play the first two Encounters to understand the story?
It is strongly recommended. The Second Encounter ends on a cliffhanger with Sam departing in a Sirian spacecraft, and The Third Encounter picks up from that moment. Knowing Sam, Mental, and the Sirian lore makes the narrative much easier to follow.
Q: When will more storyline details be revealed?
The game is currently in early development with a TBA release date. Story details, trailers, and level information will come through the official Steam page and Croteam's channels as development advances.