Time is a player’s most precious resource. Use it wisely. Do not create time-sinks for the sake of taking up their time. Don’t make them waste their time doing things that aren’t fun in order to get to things that are. Don’t arbitrarily create timers that will be likely to spend a player’s time. Don’t make a death penalty that needlessly makes a player sit around doing nothing. This is a fairly straightforward lesson, but it’s easy to violate if you aren’t careful.
Some time-wasters are fairly obvious. For example, you don’t want to make a death penalty that makes a player uselessly weak for 15 minutes. You’ve just wasted a quarter of an hour of a player’s time. Some are a little more subtle. For example, if you make a daily instance run/quest/whatever have a 24 hour no-repeat timer, you’re going to waste a player’s time. Why? If I complete the quest at 8:00PM on day 1, I can’t do it until 8:00PM on day 2. It takes me 10 minutes to do it, so on day 3, I can’t do it until 8:10PM. I might also fail to start the quest instantly, so I will slowly push the time I can do the quest later and later. How do you solve it? Either make the daily timer actually correspond to once a day (e.g. you can do it on Monday, and Tuesday, and Wednesday, and so on) or adjust the timer back from 24 hours (to something like 22 hours).
This extends to poor quest design as well which is, again, a fairly subtle thing. Do you have the player searching for 3 copies of an object that only drops 10% of the time? That could theoretically take forever. Instead, you should institute a fail-safe system that prevents this worst case scenario. How? Check out this drop chance escalation simulation. In short, every time a player fails to get quest loot, they are more likely to get it on the next try. You can also calculate the maximum kills necessary for any scenario. And, if you’re into pain, you can look at the normal way of doing things. (Note: Please don’t use these TOO much or you could make the web server very sad and I might have to take them down. Thanks!)
A player’s time should never be needlessly wasted. It is a valuable resource and should always be treated respectfully.