NXT was first teased at RuneFest 2014 as the evolution of the scrapped HTML5 client, though work on NXT had been underway for around two and a half years. NXT aimed to deliver better performance over the existing Java-based client, better graphics than the previously planned HTML5 client, and more platform and operating system support. One of the core design goals of the new client was the ability to load a larger map area and preload maps in the background.
There were weekly Developer Blogs published in early 2016 to show the progress of NXT's development.
To display NXT's capabilities, a showcase of in-game areas called Benedict's World Tour was added into the game on release. It was started by talking to Benedict Encumberyak in Burthorpe or Prifddinas. To complete the tour, players had to follow a scrapbook of clues, which led them to stand in specific locations and collect objects. Players had to use the NXT client to take part in the tour.
After the release of NXT, Jagex plans to phase out the use of the Game Client to free up resources to make further improvements to NXT, rather than continuing to maintain two clients. The timescale for phasing out the Java client will be based on beta data. Players using NXT will be playing with users of the old Java client, and will keep their progress.
Increased draw distance and ability to see players and NPCs from further away than before. The player will be able to see a bit less than the "size of Lumbridge Castle around you in a square" when playing on maximum settings. The maximum draw distance with NXT will be 4x more than that of the Java client. Loading for distant map squares will be based on rendering most important objects first.
Fully dynamic lighting and shadows. Shadows will be cast in real time, rather than being spot shadows, and will fall onto the player's character and other scenery rather than being cast onto walls and floors.
Improved water with normal mapping of waves; real-time reflection of objects and shadows, including the character's shadow, in the water; and refraction (seeing objects through water when objects are underwater).
Fog augmented with physically correct atmospheric scattering. This will remove harsh cut-offs in fog, with a fade to "haze" in the distance.
Use of MSAA anti-aliasing rather than the previously used FXAA anti-aliasing.
NXT will be going back to using Java sky domes, rather than the current cubic environment maps from HTML5, so that the Art Team do not have to maintain 2 sets of sky boxes.
Better performance and visuals than Java-based client on all machines. More capable PCs will have exponentially better performance.
No difference between DirectX and OpenGL graphics modes. OpenGL will be the preferred display mode, but DirectX will be indirectly supported as a fallback for OpenGL when graphics cards are not able to work correctly with OpenGL. OpenGL has been selected due to its superior cross-platform support and backwards compatibility - OpenGL 2.0 will be the minimum possible supported.
More efficient processor core management. Multiple cores will be made use of in loading and creating new rendering assets as well as helping with increased draw distance. Focused on SIMD and memory/cache optimisation so that even players with single core CPUs can experience good performance and players with 2 cores can achieve ideal in-game performance. Loading times and stutter when moving between areas will be improved further on machines with more than 2 cores. A CPU supporting at least SSE 2 will be required.
Will support dedicated and mobile graphics cards, automatically using the dedicated graphics card when possible.
NXT will have support for 32 and 64 bit Windows, with its installer automatically detecting which version is needed. Performance may be slightly better using 64-bit. Initially there will only be support for a 64 bit version for Linux. Windows XP will be supported.
Will be possible to run multiple clients at the same time, but this will affect performance, especially on older, single core PCs.
Players can enable Vsync to lock the FPS to the monitor's refresh rate; however, this can be turned off to provide an uncapped FPS.
Equal performance between equivalent Nvidia and AMD GPUs. A Radeon HD 7770 or a GeForce GTX 460 will be able to max out NXT at 1080p 60 fps. NXT even works on cards like the Nvidia GeForce 6150 from 2005 and the ATI Radeon 9800 from 2003.
With Intel HD graphics and an Intel Core i3 or better CPU players will be able to play at 60 fps with better graphics quality than in Java. Intel GPUs from before the HD series, e.g. X3100, GMA 945 or the Intel 4 series should be able to play at 10-15 fps.
Currently 2 GB of RAM is enough to run NXT at lower draw distances, while 3 GB is necessary for higher settings. Actual system memory consumption is around 1GB, at lower settings, to around 2GB, at max.
No browser version will be available on release. This is due to lack of support, e.g. lack of support for threads, and performance problems when using browsers.
NXT is not currently supported on tablets and mobiles. Will support mobile when mobile client is released.
Uses more storage space because more data is stored uncompressed. It will use at most 10GB of space, compared to 4GB with the Java client. NXT will have more offline processing of assets. As with the current client, players will be able to play the NXT client immediately after downloading it. The 10GB cache will be downloaded in the background. The download size will be around 1.9GB as data will be compressed during transmission.
It will not be possible to see players on other levels. Though it is possible for this to be enabled, Jagex has decided not to do so as there are some graphical glitches. Summoning familiars like Steel Titans and enemies like Gargoyles, for example, would poke up through the floor. Thus, it will not be activated until this and other issues are fixed.
A crash/freeze during/after playing certain cutscenes has been fixed.
A crash due to array overflows has been fixed.
OSX input fixes:
The Cmd+Q hotkey has been fixed.
Various Cmd hotkeys (especially Shift+Cmd+4 and Cmd+Tab) leaving Shift/Cmd buttons held down on OS X and blocking
mouse input until they are pressed again have been fixed.
Slow scrolling with mouse wheel is no longer ignored, and scrolls by a small amount as it should.
A black bar at top in fullscreen mode on OSX has been fixed.
A rare script-related crash has been fixed.
A crash caused by NPC hint arrows has been fixed.
Several potential crashes in the audio system have been fixed.
Distance fog no longer turns objects white in the background.
The mini-menu now has the correct priority for certain camera angles.
The client icon no longer appears as a terminal on OSX.
A crash caused by dragging certain interfaces has been fixed.
An animation subsystem has been optimised.
Model loading has been optimised.
An issue where some wall pieces were not correctly lit has been fixed.
Compact install on the NXT launcher has been fixed.