| 5101 | Idle Spiral - Daily Spiral Pack | 1969890 | DLC | — | Catalogue |
| 5102 | Idle Spiral - Pixel Pack | 2757040 | DLC | — | Catalogue |
| 5103 | Idle Spiral - Railway Pack | 2798570 | DLC | — | Catalogue |
| 5104 | Idle Spiral - Snake Pack | 1935210 | DLC | — | Catalogue |
| 5105 | Idle Spiral - Space Pack | 2018160 | DLC | — | Catalogue |
| 5106 | Idle Spiral - Water Pack | 2609010 | DLC | — | Catalogue |
| 5107 | Idle Spiral - Window Glass Spiral Pack | 3045480 | DLC | — | Catalogue |
| 5108 | Idle Transport Tycoon - Supporter Pack | 4424460 | DLC | — | Catalogue |
| 5109 | Idle Waters - Supporter Pack | 3769100 | DLC | — | Catalogue |
| 5110 | Idle Wizard - Bat Hunter Pack | 3856390 | DLC | — | Catalogue |
| 5111 | Idle Wizard - Expedition Pack | 3939820 | DLC | — | Catalogue |
| 5112 | Idle Wizard - Gatherer Pack | 4181890 | DLC | — | Catalogue |
| 5113 | Idle Wizard - Renown Pack | 4848150 | DLC | — | Catalogue |
| 5114 | Idle Xanxia - Core Disciple Supporter Pack | 4732470 | DLC | — | Catalogue |
| 5115 | Idle Xanxia - Supporter Pack | 4658770 | DLC | — | Catalogue |
| 5116 | Idlequarium - Age of Mechs DLC | 4307250 | DLC | — | Catalogue |
| 5117 | Idlequarium - Supporter Pack | 4176990 | DLC | — | Catalogue |
| 5118 | If On A Winter's Night, Four Travelers - Supporter Pack | 1628970 | DLC | — | Catalogue |
| 5119 | Ignis Universia - Overpriced DLC | 1484670 | DLC | — | Catalogue |
| 5120 | Ijiaru Oneesann No Otsumami 2 - Deluxe Pack | 1966160 | DLC | — | Catalogue |
| 5121 | Ikeda - Gold Edition DLC | 1139852 | DLC | — | Catalogue |
| 5122 | Ikkarus and the Prince of Sin - Art Pack | 2504910 | DLC | — | Catalogue |
| 5123 | Ikonei Island - Lunar Union Festival Content Pack | 2845680 | DLC | — | Catalogue |
| 5124 | Ikonei Island - Lystide Content Pack | 2841850 | DLC | — | Catalogue |
| 5125 | Ikonei Island - Spring Tide Content Pack | 2869700 | DLC | — | Catalogue |
| 5126 | Illegal Mahjong R18 DLC | 2725740 | DLC | — | Catalogue |
| 5127 | Immortal Empire - Adventurer Pack | 465832 | DLC | — | Catalogue |
| 5128 | Immortal Empire - Master Pack | 465834 | DLC | — | Catalogue |
| 5129 | Immortal Empire - Mercenary Pack | 465833 | DLC | — | Catalogue |
| 5130 | Immortal: Unchained - Primes Pack | 883210 | DLC | — | Catalogue |
| 5131 | Immortals Fenyx Rising™ - Season Pass | 2224320 | DLC | — | Catalogue |
| 5132 | Imperator: Rome - Epirus Content Pack | 978951 | DLC | — | Catalogue |
| 5133 | Imperator: Rome - Heirs of Alexander Content Pack | 1437660 | DLC | — | Catalogue |
| 5134 | Imperator: Rome - Magna Graecia Content Pack | 1252870 | DLC | — | Catalogue |
| 5135 | Imperator: Rome - The Punic Wars Content Pack | 1173860 | DLC | — | Catalogue |
| 5136 | ImpossiBowl - Supporter DLC | 3008370 | DLC | — | Catalogue |
| 5137 | Impostor Mode DLC | 2306170 | DLC | — | Catalogue |
| 5138 | Incredicer - Supporter Pack | 4173070 | DLC | — | Catalogue |
| 5139 | Incremental Dungeon - Supporter Pack | 4352850 | DLC | — | Catalogue |
| 5140 | Incremental Epic Breakers - Automation Pack | 1571902 | DLC | — | Catalogue |
| 5141 | Incremental Epic Breakers - Daily Quest Pack | 1571901 | DLC | — | Catalogue |
| 5142 | Incremental Epic Breakers - Epic Pack | 1571903 | DLC | — | Catalogue |
| 5143 | Incremental Epic Breakers - Starter Pack | 1571900 | DLC | — | Catalogue |
| 5144 | Incremental Epic Hero - Global Skill Slot Pack | 1555851 | DLC | — | Catalogue |
| 5145 | Incremental Epic Hero - IEH2 Support Pack | 1580930 | DLC | — | Catalogue |
| 5146 | Incremental Epic Hero - Monster Gold Cap Pack | 1555853 | DLC | — | Catalogue |
| 5147 | Incremental Epic Hero - Premium Nitro Pack | 1555852 | DLC | — | Catalogue |
| 5148 | Incremental Epic Hero - Starter Pack | 1555850 | DLC | — | Catalogue |
| 5149 | Incremental Epic Hero 2 - Global Skill Slot Pack | 2053802 | DLC | — | Catalogue |
| 5150 | Incremental Epic Hero 2 - Inventory Slot Expansion Pack | 2053803 | DLC | — | Catalogue |
| 5151 | Incremental Epic Hero 2 - Premium Nitro Pack | 2053801 | DLC | — | Catalogue |
| 5152 | Incremental Epic Hero 2 - Starter Pack | 2053800 | DLC | — | Catalogue |
| 5153 | Incrempire - Supporter Pack | 4776290 | DLC | — | Catalogue |
| 5154 | Incubus - HD Textures Pack | 2597860 | DLC | — | Catalogue |
| 5155 | Incursion2D - Founder Pack | 2874100 | DLC | — | Catalogue |
| 5156 | Indie Game: The Movie Special Edition DLC | 207090 | DLC | — | Catalogue |
| 5157 | Industry Giant 4.0 - Digital Supporter Pack | 3225390 | DLC | — | Catalogue |
| 5158 | Industry Idle - Expansion Pack 1 | 1577540 | DLC | — | Catalogue |
| 5159 | Industry Idle - Expansion Pack 2 | 1807800 | DLC | — | Catalogue |
| 5160 | Industry Manager: Future Technologies - Awesome Products Pack | 444360 | DLC | — | Catalogue |
| 5161 | Inertial Drift - Twilight Rivals DLC | 2075290 | DLC | — | Catalogue |
| 5162 | Infection Crisis: Fight For Life - Support DLC | 2619380 | DLC | — | Catalogue |
| 5163 | Infection Free Zone - Supporter Pack | 3905440 | DLC | — | Catalogue |
| 5164 | Infinite Cards - Support DLC | 4945110 | DLC | — | Catalogue |
| 5165 | Infinite Jump-DLC | 1571850 | DLC | — | Catalogue |
| 5166 | Infinite Survival - Monster Pack | 871340 | DLC | — | Catalogue |
| 5167 | Infinity Wars - Rise of the Rifts Campaign Pack | 4695450 | DLC | — | Catalogue |
| 5168 | Influent DLC - Cymraeg [Learn Welsh Language] | 435514 | DLC | — | Catalogue |
| 5169 | Influent DLC - Dansk [Learn Danish Language] | 435510 | DLC | — | Catalogue |
| 5170 | Influent DLC - Deutsch [Learn German Language] | 286970 | DLC | — | Catalogue |
| 5171 | Influent DLC - English [Learn English Language] | 286962 | DLC | — | Catalogue |
| 5172 | Influent DLC - Español [Learn Spanish Language] | 286964 | DLC | — | Catalogue |
| 5173 | Influent DLC - Français [Learn French Language] | 286963 | DLC | — | Catalogue |
| 5174 | Influent DLC - Italiano [Learn Italian Language] | 297841 | DLC | — | Catalogue |
| 5175 | Influent DLC - Latina [Learn Latin Language] | 286972 | DLC | — | Catalogue |
| 5176 | Influent DLC - Magyar [Learn Hungarian Language] | 435512 | DLC | — | Catalogue |
| 5177 | Influent DLC - Nederlands [Learn Dutch Language] | 435515 | DLC | — | Catalogue |
| 5178 | Influent DLC - Norsk [Learn Norwegian Language] | 338370 | DLC | — | Catalogue |
| 5179 | Influent DLC - Polski [Learn Polish Language] | 435513 | DLC | — | Catalogue |
| 5180 | Influent DLC - Português [Learn Portuguese Language] | 297842 | DLC | — | Catalogue |
| 5181 | Influent DLC - Português do Brasil [Learn Brazilian Portuguese Language] | 338371 | DLC | — | Catalogue |
| 5182 | Influent DLC - Pусский [Learn Russian Language] | 297840 | DLC | — | Catalogue |
| 5183 | Influent DLC - Suomi [Learn Finnish Language] | 338372 | DLC | — | Catalogue |
| 5184 | Influent DLC - Svenska [Learn Swedish Language] | 286965 | DLC | — | Catalogue |
| 5185 | Influent DLC - Українська [Learn Ukrainian Language] | 435511 | DLC | — | Catalogue |
| 5186 | Influent DLC - български [Learn Bulgarian Language] | 286960 | DLC | — | Catalogue |
| 5187 | Influent DLC - हिन्दी [Learn Hindi Language] | 435519 | DLC | — | Catalogue |
| 5188 | Influent DLC - 日本語 [Learn Japanese Language] | 286966 | DLC | — | Catalogue |
| 5189 | Influent DLC - 普通话 [Learn Mandarin Chinese Language] | 286961 | DLC | — | Catalogue |
| 5190 | Influent DLC - 한국어 [Learn Korean Language] | 286971 | DLC | — | Catalogue |
| 5191 | Inheritance: Ladeina's Path - Expansion Bundle | 2395090 | DLC | — | Catalogue |
| 5192 | Inheritance: Ladeina's Path - Nude Mod Expansion Pack | 2212240 | DLC | — | Catalogue |
| 5193 | Initial Drift Online - Car Pack | 2352971 | DLC | — | Catalogue |
| 5194 | Injection π23 NNNN Expansion Events | 2664480 | DLC | — | Catalogue |
| 5195 | Injoku Byoutou - Deluxe Pack | 1822480 | DLC | — | Catalogue |
| 5196 | Injoku Furin - Deluxe Pack | 1573260 | DLC | — | Catalogue |
| 5197 | Injustice™ 2 - Demons Shader Pack | 731150 | DLC | — | Catalogue |
| 5198 | Injustice™ 2 - Gods Shader Pack | 731160 | DLC | — | Catalogue |
| 5199 | Injustice™ 2 - Ultimate Pack | 734280 | DLC | — | Catalogue |
| 5200 | Ink Hero DLC | 1197170 | DLC | — | Catalogue |
![Influent DLC - Cymraeg [Learn Welsh Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/435514/header.jpg)
![Influent DLC - Dansk [Learn Danish Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/435510/header.jpg)
![Influent DLC - Deutsch [Learn German Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/286970/header.jpg)
![Influent DLC - English [Learn English Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/286962/header.jpg)
![Influent DLC - Español [Learn Spanish Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/286964/header.jpg)
![Influent DLC - Français [Learn French Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/286963/header.jpg)
![Influent DLC - Italiano [Learn Italian Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/297841/header.jpg)
![Influent DLC - Latina [Learn Latin Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/286972/header.jpg)
![Influent DLC - Magyar [Learn Hungarian Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/435512/header.jpg)
![Influent DLC - Nederlands [Learn Dutch Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/435515/header.jpg)
![Influent DLC - Norsk [Learn Norwegian Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/338370/header.jpg)
![Influent DLC - Polski [Learn Polish Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/435513/header.jpg)
![Influent DLC - Português [Learn Portuguese Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/297842/header.jpg)
![Influent DLC - Português do Brasil [Learn Brazilian Portuguese Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/338371/header.jpg)
![Influent DLC - Pусский [Learn Russian Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/297840/header.jpg)
![Influent DLC - Suomi [Learn Finnish Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/338372/header.jpg)
![Influent DLC - Svenska [Learn Swedish Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/286965/header.jpg)
![Influent DLC - Українська [Learn Ukrainian Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/435511/header.jpg)
![Influent DLC - български [Learn Bulgarian Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/286960/header.jpg)
![Influent DLC - हिन्दी [Learn Hindi Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/435519/header.jpg)
![Influent DLC - 日本語 [Learn Japanese Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/286966/header.jpg)
![Influent DLC - 普通话 [Learn Mandarin Chinese Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/286961/header.jpg)
![Influent DLC - 한국어 [Learn Korean Language] Steam header image](https://cdn.cloudflare.steamstatic.com/steam/apps/286971/header.jpg)
