| ngb | NonoPocket Nonogram Puzzle Data |
| ngn | Fly! Data File |
| nh | NetHack Game Configuration File |
| nif | NetImmerse Data File |
| nip | D2NT NIP File |
| nl2script | NoLimits 2 Script |
| nlelem | NoLimits Track Element |
| nlpack | NoLimits Roller Coaster Track Package |
| nlpx | NoLimits RCS Package |
| nltrack | NoLimits Roller Coaster Track Data |
| nml | NSMB Editor Exported Level |
| nnt | Close Combat 3 Game Data |
| nob | Vampire: The Masquerade Archive |
| node | For Honor EasyAntiCheat Data |
| npa | Steins: Gate Archive |
| npj | Delta Force Game Mission Data |
| nsbca | Nintendo DS Model Animation |
| nsbtx | Nintendo DS Model Texture |
| nsbva | Nintendo DS Visibility Animation |
| nsz | Rumble Fighter Data |
| ntj | D2NT Settings File |
| ntl | D2NT Library |
| ntrk | Pacific Fighters Online Track |
| nus3conf | Ultimate Ninja Storm 4 Sound Config |
| nw | GraalOnline Level Data |
| nwx | Outlaws Choreography Data |
| nx | MapleStory NX Package |
| nx3 | Rappelz NX3 Data |
| o3d | OMSI 3D Data |
| oa0 | B.O.U.T. Evolution Texture Data |
| oac | Grand Theft Auto V Audio Data |
| oav | Microsoft Flight Simulator Texture Data |
| obg | OpenTTD OpenGFX Base Graphics Data |
| odr | OpenIV Model Data |
| ogf | Stalker Model Data |