Free Moddable Games on Steam
Steam currently has 1,633 Moddable games available to download and play. Explore our list of the best free games ranked by popularity and ratings. Data for this list is calculated from reviews and player counts reported directly by Steam and will be updated in real-time. Free Moddable game rankings were last updated on 8/4/2025.
Looking for more? Explore other lists such as:
- Best moddable games on Steam
- Best moddable Steam Deck games
- Best moddable Steam games for Mac OS
- Best moddable Linux games on Steam
- Free Steam games
- Most played Steam games
- Best rated Steam games
1. Counter-Strike 2
For over two decades, Counter-Strike has offered an elite competitive experience, one shaped by millions of players from across the globe. And now the next chapter in the CS story is about to begin. This is Counter-Strike 2.
Counter-Strike 2 holds the #1 spot for "best free Moddable game on Steam" with a Player Score of 86. Its score was calculated by analyzing a total of 8,933,503 reviews on Steam. This breaks down to a total of 7,728,139 positive reviews and 1,205,364 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on both Windows and Linux systems. At the moment, it is possible to play Counter-Strike 2 on the Steam Deck (though some functionality may be limited).
2. tModLoader
Dig, Fight, and Build your way through the world of player-created mods on Terraria with tModLoader - this DLC makes modding Terraria a reality!
tModLoader has achieved a Player Score of 96, placing it in the #2 spot for the best free Moddable games. Its score was calculated by analyzing a total of 323,016 reviews on Steam. This breaks down to a total of 313,656 positive reviews and 9,360 negative reviews — making it "Overwhelmingly Positive" on Steam.
It can be played and ran on Windows, Mac, and Linux systems. At the moment, it is possible to play tModLoader on the Steam Deck (though some functionality may be limited).
3. Blender
Blender is the free and open source 3D creation suite. Free to use for everyone, for any purpose.
Blender has achieved a Player Score of 95, placing it in the #3 spot for the best free Moddable games. Its score was calculated by analyzing a total of 75,257 reviews on Steam. This breaks down to a total of 72,445 positive reviews and 2,812 negative reviews — making it "Overwhelmingly Positive" on Steam.
It can be played and ran on Windows, Mac, and Linux systems. At the moment, it is not possible to play or run Blender on the Steam Deck.
| Release Date | 4/24/2015 |
| Developer | Blender Foundation |
| Publisher | Blender Foundation |
| Steam App Id | 365670 |
4. VPet-Simulator
Feeling like the computer desktop is too dull? Need something cute to heal oneself? Come and try this new completely free and open source V-Pet simulator. A cute and adorable pet that supports various feeding interactions to accompany you in game learning is definitely your best choice!
VPet-Simulator has achieved a Player Score of 96, placing it in the #4 spot for the best free Moddable games. Its score was calculated by analyzing a total of 47,055 reviews on Steam. This breaks down to a total of 46,257 positive reviews and 798 negative reviews — making it "Overwhelmingly Positive" on Steam.
It can be played and ran on Windows systems. At the moment, it is not possible to play or run VPet-Simulator on the Steam Deck.
5. Age of Empires III: Definitive Edition
Age of Empires III: Definitive Edition offers players a trial of this historical single & multiplayer RTS experience. *Note: To unlock all features of the game please see the “Base Game” product.
Age of Empires III: Definitive Edition has achieved a Player Score of 83, placing it in the #5 spot for the best free Moddable games. Its score was calculated by analyzing a total of 49,235 reviews on Steam. This breaks down to a total of 41,759 positive reviews and 7,476 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on Windows systems. At the moment, it is possible to play Age of Empires III: Definitive Edition on the Steam Deck (though some functionality may be limited).
| Release Date | 10/15/2020 |
| Franchise | Age of Empires Franchise |
| Developers | |
| Publisher | Xbox Game Studios |
| Steam App Id | 933110 |
6. Crusader Kings II
Explore one of the defining periods in world history in an experience crafted by the masters of Grand Strategy.
Crusader Kings II has achieved a Player Score of 89, placing it in the #6 spot for the best free Moddable games. Its score was calculated by analyzing a total of 72,641 reviews on Steam. This breaks down to a total of 65,791 positive reviews and 6,850 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on Windows, Mac, and Linux systems. At the moment, it is possible to play Crusader Kings II on the Steam Deck (though some functionality may be limited).
| Release Date | 2/14/2012 |
| Franchise | Crusader Kings Official |
| Developer | Paradox Development Studio |
| Publisher | Paradox Interactive |
| Steam App Id | 203770 |
7. Source Filmmaker
The Source Filmmaker (SFM) is the movie-making tool built and used by us here at Valve to make movies inside the Source game engine. Because the SFM uses the same assets as the game, anything that exists in the game can be used in the movie, and vice versa.
Source Filmmaker has achieved a Player Score of 91, placing it in the #7 spot for the best free Moddable games. Its score was calculated by analyzing a total of 41,124 reviews on Steam. This breaks down to a total of 38,212 positive reviews and 2,912 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on Windows systems. At the moment, it is not possible to play or run Source Filmmaker on the Steam Deck.
8. DDNet
Want to play the hardest cooperative 2D platformer ever? Want to finish no map ever? Want to be in pain for hours and cry, getting nothing in return? Come play DDNet with a large community of other sufferers!
DDNet has achieved a Player Score of 87, placing it in the #8 spot for the best free Moddable games. Its score was calculated by analyzing a total of 38,808 reviews on Steam. This breaks down to a total of 34,543 positive reviews and 4,265 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on Windows, Mac, and Linux systems. At the moment, it is possible to play DDNet on the Steam Deck (though some functionality may be limited).
| Release Date | 8/17/2020 |
| Developer | DDNet Team |
| Publisher | DDNet Team |
| Steam App Id | 412220 |
9. OpenTTD
OpenTTD is a business simulation game in which players earn money by transporting passengers and cargo via road, rail, water, and air. It is an open-source remake and expansion of the 1995 Chris Sawyer video game Transport Tycoon Deluxe.
OpenTTD has achieved a Player Score of 94, placing it in the #9 spot for the best free Moddable games. Its score was calculated by analyzing a total of 14,726 reviews on Steam. This breaks down to a total of 14,163 positive reviews and 563 negative reviews — making it "Overwhelmingly Positive" on Steam.
It can be played and ran on Windows, Mac, and Linux systems. At the moment, it is possible to play OpenTTD on the Steam Deck (though some functionality may be limited).
10. Alien Swarm: Reactive Drop
Co-operative top-down shooter game available for free. An epic bug hunt featuring a unique blend of co-op play and squad-level tactics.
Alien Swarm: Reactive Drop has achieved a Player Score of 93, placing it in the #10 spot for the best free Moddable games. Its score was calculated by analyzing a total of 22,824 reviews on Steam. This breaks down to a total of 21,665 positive reviews and 1,159 negative reviews — making it "Very Positive" on Steam.
It can be played and ran on Windows systems. At the moment, it is not possible to play or run Alien Swarm: Reactive Drop on the Steam Deck.
| Release Date | 4/20/2017 |
| Developer | Reactive Drop Team |
| Publisher | Reactive Drop Team |
| Steam App Id | 563560 |
More Free Moddable Games
Explore even more rankings for the 100 best free Moddable games available on Steam.
| Image | Name | Actions | ||||
|---|---|---|---|---|---|---|
| 646,719 | 8/21/2012 | 86 | Free | Steam Charts | |
| 26,299 | 5/16/2020 | 96 | Free | Steam Charts | |
| 9,062 | 4/24/2015 | 95 | Free | Steam Charts | |
| 4,644 | 8/13/2023 | 96 | Free | Steam Charts | |
| 3,339 | 10/15/2020 | 83 | Free | Steam Charts | |
| 1,289 | 2/14/2012 | 89 | Free | Steam Charts | |
| 1,020 | 7/10/2012 | 91 | Free | Steam Charts | |
| 968 | 8/17/2020 | 87 | Free | Steam Charts | |
| 410 | 4/1/2021 | 94 | Free | Steam Charts | |
| 314 | 4/20/2017 | 93 | Free | Steam Charts | |
 | 265 | 11/17/2021 | 68 | Free | Steam Charts | |
 | 243 | 1/22/2016 | 92 | Free | Steam Charts | |
 | 196 | 7/1/2014 | 66 | Free | Steam Charts | |
 | 195 | 5/6/2021 | 88 | Free | Steam Charts | |
 | 179 | 4/30/2015 | 76 | Free | Steam Charts | |
 | 179 | 4/14/2023 | 93 | Free | Steam Charts | |
 | 163 | 6/25/2021 | 91 | Free | Steam Charts | |
 | 162 | 6/2/2025 | 69 | Free | Steam Charts | |
 | 128 | 2/15/2023 | 75 | Free | Steam Charts | |
 | 123 | 1/6/2024 | 94 | Free | Steam Charts |
Soures & References
Steambase has best-in-class data powered directly by Steam, our data partners, and in-house experts. Player counts and rankings are enriched, analyzed, and updated in real-time to ensure we surface the most up-to-date insights. Learn more about the Steambase approach to data collection and our review methodology.
- Valve Corporation. (2025, August 4). Steam Store. Steam Store.
- Valve Corporation. (2025, August 4). Counter-Strike 2 on Steam. Steam Store.
- Valve Corporation. (2025, August 4). tModLoader on Steam. Steam Store.
- Valve Corporation. (2025, August 4). Blender on Steam. Steam Store.
- Valve Corporation. (2025, August 1). VPet-Simulator on Steam. Steam Store.
- Valve Corporation. (2025, August 3). Age of Empires III: Definitive Edition on Steam. Steam Store.
- Valve Corporation. (2025, May 14). Crusader Kings II on Steam. Steam Store.
- Valve Corporation. (2025, July 17). Source Filmmaker on Steam. Steam Store.
- Valve Corporation. (2025, August 4). DDNet on Steam. Steam Store.
- Valve Corporation. (2025, August 4). OpenTTD on Steam. Steam Store.
- Valve Corporation. (2025, August 1). Alien Swarm: Reactive Drop on Steam. Steam Store.