Sometimes something is updated in a way it's not a "sequel", more of a "sidequel" if you will. RPG Maker 2003 is largely based on its predecessor RPG Maker 2000, but does not depart from its basic concepts and largely reuses the same systems and ideas. Instead, it provides some different features that its predecessor did not.

RPG Maker 2003's largest change is the default "side-view" battle system, much like the Final Fantasy games on the NES/SNES, as opposed to the "front-view" battle mode seen in games like Dragon Quest. There are some improvements to some 2000 features, but this is quite minor compared to the change in the battle system, as the two are otherwise nigh identical under the hood.

Like every other maker in the series, this is a top-down, 2D tile-based RPG creation engine. Control is done with the keyboard and mouse to change database objects and create maps. There are two layers on maps, an upper and lower layer, which allows some illusion of height mapping or placing some map areas above others. For example, being able to walk under certain overhanging objects. Aside from maps, customization of your game is limited to whatever tweaks you make in the database and whatever resources you use, either the default ones or those provided from other sources.

Graphically, the style is quite simple, very early NES style fantasy graphics. very reminiscent of the Dragon Quest series. Character sprites are tall, not super-deformed like in later makers, and they also fit the high fantasy NES style. Enemy battler graphics have a bright and cartoony motif, as the color palette is limited as was standard on early, Windows-based computers. Resource graphics are limited to BMP, PNG, and the now nearly extinct XYZ format, retained for compatibility reasons with older projects from the original release era.

Sound is rendered in chiptune style MIDI, though WAV and MP3 formats can be used and uploaded for one's projects if they prefer. The sound effects and music again fit the high fantasy RPG aesthetic perfectly. Controls are limited to the keyboard when playtesting or playing games made with the engine, though the mouse is available when using the editor itself.

While a lot of the above is true for RPG Maker 2000, there are some changes. Due to supporting side-view battle modes, there are now options for character animations in combat you can modify and import new graphics for. The enemy battlers take a lot of inspiration from the Shin Megami Tensei games, having a pronounced "mythological potpourri" theme. The engine still has no custom scripting, but the eventing engine has been improved to the point one could greatly modify the battles to have features only scripting would make possible in later makers.

The stability is slightly better than in 2000. Full-screen mode scales better and with much more fidelity than in 2000. The color palette is slightly less washed out in this mode as well, so the overall quality is far less impacted even on very wide monitors. This program also runs with a decent degree of success using Wine/Proton in Linux.

There is an interesting "amnesty" built into the program for those who used the pirated version of 2003. It is possible to import a project made used the pirated version and update key files in it to work with the modern fixes so they will function properly. It's not perfect, some graphics files in the pirated and legitimate versions were named differently, meaning some improperly referenced graphics will need to be fixed manually. Some database information may not port completely intact as well. Otherwise, this allows those who used the pirated version to legitimize their games for distribution with modern-day updates.

Morally, we have a bit more to be concerned about compared to RPG Maker 2000.

Violence is of the turn-based RPG variety, should the creator of a game choose to include any combat. Language is entirely up to the creator to decide if they want to remain clean or profane as well.

Sexual content is somewhat more prevalent in the enemy battler graphics. Even though it is in very low resolution, there is some partial female nudity for some of the female monsters. Some enemy battlers in the stock content reference necromancers and demons in terms of names and depictions. There are no occult references like pentagrams in the stock art files, and any references to anything of an occult nature are purely up to game designers otherwise. Any degree of unethical behavior is also up to the developer, should they wish to include it.

Overall, since buying this fairly cheap program gives you a license to use its assets in other RPG Maker programs, it worth buying if that is your goal or you want to make an RPG game on a very retro-based engine. The latter can be done with custom art and music on the later engines, so you may not find this ideal if you intend to go that route. Morally, this is somewhat less tame than its predecessor if you stick with the stock resources, though otherwise suitable for all ages. While not my personal favorite from the franchise by any means, I'm still pleased to say it is a worthy purchase for diehard RPG Maker fans.