Accessibility is, much like the "fun factor", an almost random element to a game. Most people never really grasp what makes a game accessible, but there are a few really important things that you can point at and say, "Yes, this makes a game much more accessible for me! Thank you for including it!" So let's run down the basics, shall we?

Controls are the biggest point where a player can be won or lost. Penny Arcade did a great comic on this topic, as seen above. The more complicated your controls, the less accessible your game will be. You want things to be as simple as possible with a minimum of fighting the game to get your character to do the things you want it to do. Trespasser is a great example of a game that fails with controls, and Within a Deep Forest is an example of a game that is extremely easy to pick up thanks to a very simple control scheme. When in doubt, keep it simple. Also, to note: in general, PC players rest their right hand on the arrow keys and their left hand on ZXC when playing a keyboard only game. This is a good default scheme to use. However, you should always allow players to configure keys how they want.

Interface sort of ties into controls, but it's not the same thing. You can have a phenomenal control scheme and a terrible interface or vice-versa. To make a good interface, you need to balance out a few things:

1. Relevance is incredibly important, and for good reason. Players want information that is most relevant to them in general play at all times. Don't clutter up your interface with unneeded icons that serve an actual purpose fairly rarely. Things such as health, mana, money, and such are pretty important to the player and should not be cluttered with stamina, potential max health, stress, or any number of additional bars that could be added to muck up the works.
2. Detail is, paradoxically, also important. Players want to be in the loop as much as possible, meaning you have to give them the information they want. If they have a health bar, show them the amount of health they have numerically. If you have a particular weapons or spell, list its effects and other attributes. If you are building something, list the required materials and perhaps other buildings it links to. Players want to know what is going on!

These two attributes are opposites to each other, but extremely important. If you have relevance but no detail, players feel like you are holding things back from them. If you have detail but no relevance, players get overwhelmed by the interface and begin to feel lost and confused while trying to play. If you've ever tried to play Dwarf Fortress, you definitely know what that feels like! A good example of a game that strikes a balance between relevance and detail is Civilization IV. For most players, they will have access to the relevant information they need for average play. For the experts, the game allows them to plumb into much more detail with ease, letting them micromanage their empires to perfection. It's a great balance that pleases both sides.

Gameplay concepts are another big one. In general, this is the least important in accessibility but most important in attracting new players. A game that allows you to plumb a new random dungeon each time you play with millions of variations and intense combat sounds like a great game! But it is Nethack, which is like running into a brick wall for most people due to the extremely punishing gameplay, hard-to-learn interface, and unusual controls. In general, try to balance the awesome factor with simplicity so that players don't get confused trying to play your incredible game. On a similar note, players generally don't want gameplay that punishes them hard and unfairly for little mistakes. If you accidentally move one step to the left and immediately die, sending you to the very beginning of the game with a detrimental effect, you're going to be pissed off because it seems unfair. The general rule for these is simple: if a player can memorize, it's not unfair. This makes a most AI encounters and landscape puzzles fair. However, if the AI has a huge advantage over the player, such as SNK boss syndrome, well, you may have an unfairness problem!

If you haven't noticed, all of these categories boil down to one thing: simplicity. Players love details and complex games, don't get me wrong. But in order to make those incredible life simulations accessible, there needs to be an element of simplicity to the controls, interface, and gameplay. The simpler your game is, the more accessible it is. But this doesn't mean sacrifice good concepts for simplicity! Just refine those same concepts into something anybody can understand. For example, in World of Goo, there's a minimal interface, extremely easy-to-understand goals, and a control scheme that a grade-schooler can use without a hitch. While the puzzles may be deviously hard and addicting, the game itself is actually rather simple. Whether you are making a new match-three game or the most complicated science-fiction life simulation ever created, accessibility is an important aspect to you. After all, it determines who plays your games!

For more coverage on indie games and the scene, keep an eye out for Indie Showcase at the same bat time, same bat channel. Also check out Freeware Friday and our indie category for some excellent freeware games and indie news, respectively.