Firstly, the typos in the title are jokes. Dear all that is holy. Jokes.
The task to make the text in a game clean, consistent, and clear, is arduous and requires a great deal of time. It should come as no surprise that in the writing world there are people whose only job it is to tighten the text, ensure consistency, and improve upon the final result. I use the modifier "only" not to minimize the impact of their efforts, but to highlight the laser focus and expertise required to achieve this result.
I consider text writing and editing a part of development from the start. It's something I take very seriously from the beginning, mostly because I often design games with text on cards and I know all too well how a misinterpreted card and lead to terrible tests and disastrous results.
But, how does one go about editing and writing text to ensure it meets all your goals and leads to an excellent and clear game experience? We spent the holiday weekend going through a massive text scrub of Hocus after two pieces of feedback. These two tiny pieces made a huge positive impact and I think there's a lesson here.
Examine oft overlooked core rules and see if they can better fit on the cards. If the global rule is "discard the card after use," well, players need to remember that. Do not fill your cards with such text. But, in the case of Hocus, the global rule was "You can never modify another player's Pocket" and a quarter of our Spells said "Do something to a Pocket." It was easy for people who hadn't read the rules (and were taught the game) to interpret that text as "Do something to any pocket, mine or yours." Therefore, we added the word "your" to every card and deleted the core rule. So, now it will say "Do something to your Pocket."
Huge clarification, simple change.
Write an FAQ for every card and create examples for the ways one can conceivably use the card. Do all of these match your expectations? We have cards called Owl Wizards that can be used in a particular situation as a bonus Spell. Every turn you must do one Spell, but before or after it, you may discard an Owl Wizard to use its ability. We had two Spells that granted you additional Spells. One specifically said "Cast two Spells this turn." The intent was that you would do your normal Spell, than one additional. But, due to the global rule of discarding an Owl Wizard, one could conceivably interpret this as "Use my Spell, then discard the Owl to use two more Spells." Therefore, we revised the text to complement the core rule more smoothly.
When you write an FAQ, your brain enters a mindset of reverse engineering. You're trying to over explain things and thing of alternate paths to clarify. That's why you have an FAQ. Doing this ahead of time, not after the fact, will illustrate discrepancies and issues in your text.
When a tester is confused by a single card, ask her same question against every card. Chances are, if you thought a line of text was valid beforehand, you probably used a similar method elsewhere. In Hocus, we have 24 unique Spells and 15 Owl Wizards, all of which manipulate the same simple framework and core rules. This means when we found 1 error, we really had 5 or 6 errors.
Use terms consistently and try to align them with terms used by other games. Hand, discard, draw -- these are standards you should not change. Once you identify your key terms, examine every card to see if it effectively and consistently uses them. Find cases where you accidentally introduce a new term and see if you can remove the exception. Remember that some words are common terms, and some have the feeling of weight. They seem like they are a game term. Try to avoid these!
For example in Hocus, we said "owned" to indicate Spells controlled by a player. This felt scary to us because "own" had weight behind it. What does it mean to own a Spell? Well, nothing. It's really just the spell in front of you. We had to consider this and play thesaurus a bit to find something with less heft.
Use fewer words where possible, but when the one perfect word has too much heft behind it, instead of implying a new term, instead, use three or four words to elaborate instead.
Print your content, go away from a computer, and read it all aloud. This sounds ridiculous, but it was a tip given to me in college and I've always found it to be an intensely useful exercise. Firstly, get away from your computer. Twitter, Facebook, Board Game Arena, whatever you're playing, get away from it. You need to be focused during edits. When you're looking at something you've seen thousands of times, it's very easy for your mind to just sprint through it. Give it your entire focus and unplug.
Secondly, read it aloud. By reading aloud, you'll force your mind to actually read it and you'll find typo-like word omissions and poor spelling errors. The combination of focus and reading aloud will catch everything that the other processes missed.
Then, do everything above four more times. Then two more times.
What are your favorite tactics for proofreading and finalizing text balance?