So how are you going to build this thing? You have two options – spend some time learning a bit of scripting, or use software that requires little to none of that. It’s up to you.

Eventually, if you’re serious about indie game development, you’ll want the flexibility offered by a full understanding of programming and computer science. Right now, however, you may just be testing the waters. No problem, there are plenty of tools for nonprogrammers. I’ve arranged several popular methods in roughly the order of their complexity. Some are free and others are demos.

These are the programs I've tested the most extensively, but hit the next page for a giant list of downloads. 

Game Maker 7.0 – download 
Game Maker is an excellent piece of free software ($20 gets you more functionality). It does what it purports to, allowing you to create relatively complex 2D games with very little knowledge of programming, though it does contain a simple scripting language for more complex operations.

There is, of course, some learning to do – but it’s no more difficult than mastering a new game, and part of the reason I recommend Game Maker to beginners is its excellent community and very complete set of tutorials.

RPG Maker 2003 – download
An old favorite. Unlike Game Maker, RPG Maker does limit you to one type of game, but it does RPGs very well. It’s your basic tile-map, animated sprite character, random battle engine. The interface is well designed and easy-to-use, and the software includes a good array of pre-made graphics (though wouldn’t you rather make your own?).

A newer version, RPG Maker XP, is available, but the full license will cost you $60 USD.

RPG Toolkit – download
While it doesn't have the most refined interface, RPG Toolkit is pretty flexible, and aids in the the creation of  2D isometric RPGs. The hard stuff has been taken care of for the most part, leaving you to work out the graphics and scripted events. There's also a decent selection of tutorials on the site to help you get started.

Byond – download
Byond is an interesting tool which allows you to create small online games with relative ease. You’re going to have to learn a bit more in the way of coding than you would with something like GameMaker or RPGmaker, but if you absolutely must make an online game, this is probably the easiest way.

MUGEN – download 
MUGEN is a very popular customizable fighting engine. It's a bit less flexible than the previous entries, as your task mostly involves making new fighters and their moves (a lot of graphics and animation work). The most popular trend with MUGEN is ripping animations from existing fighting games and building custom versions of those characters. For help using MUGEN, check out mugenguild.

DarkBASIC– information
DarkBASIC is a version of the Basic programming language (which, as its name implies, is actually fairly easy to learn) built around DirectX. Despite being more challenging than something like Game Maker, it is possible to learn via online tutorials and create a quality game in DarkBasic.

The full version is priced at a very reasonable $39.99 or £20.99. Before it was sucked into "The Game Creators" a demo version was available, but they don't seem to be offering it for download anymore (they also had a much nicer, more complete website). An older demo version is available here. 

Blender – download
Blender is a free, open source 3D modeling, animation, and game design program. Since you’re dealing with 3D game creation, the learning curve is very high. For someone who isn’t frustrated or deterred easily, Blender can be a great way to get into 3D game design – just be sure you're willing to spend a lot of time reading tutorials and learning through trial and error. Just because it’s free doesn’t mean its shoddy – check out some of the work done in Blender.

Flash CS3 - information
Flash is a robust and widely used application for creating professional games, interfaces, applications, and designs for the web. It contains its own scripting language called ActionScript, which is actually fairly easy to learn. Creating a game with Flash will require more learning and tutorial reading than with some of the other software I've listed, but once you understand it, it's very flexible and lends itself well to game design. Unfortunately, it is professional software and thus comes with a professional price tag: $699 USD.

If you’d like to give it a whirl, Adobe offers a free trial.

Microsoft Visual Visual C++, Game Creators GDK – download 
For the serious enthusiast, Microsoft has released “express” versions of Visual C++, Visual Basic, The Game Creators GDK, and the Xbox 360 XNA development kit. If you don't have any programming or game design experience, don't expect to jump into it have something built in 20 minutes. A lot of stuff goes into making a game, so the most you'll initially be able to do is print "Hello World." But don't be discouraged - you can learn!