All MMORPGs have some sort of limitation of what a single character can do. That is useful in as far as it fosters cooperation between players. But it also enables a different solution: A single player opening several game accounts and controlling several characters, sometimes simultaneously. I reported on me "recruiting" myself as a "friend" for a rocket mount reward and triple xp in World of Warcraft. In some games you can only have one character per account, or only one character per account gets certain benefits, like skill training in EVE, so making a second account enables you to play alts. And in some Free2Play browser games having several accounts gives you so much of an advantage that it is actually forbidden by the rules. So this is the story of me trying out playing A Tale in the Desert with two accounts, where the only restriction is that you can't use more than one Free Trial account.
The reason I made the second account was actually a mistake I made: I had understood one of the tests in A Tale in the Desert wrong. I mentioned that there are seven disciplines in ATitD, each with 8 tests, of which one is the initiation. I had the initiation of 6 of those 7 disciplines, but was lacking the 7th initiation, to the discipline of Worship. The initiation to Worship test needs two players. They to a starting ceremony together at an altar, then one of the two players goes and performs a series of tasks, while the other player stays at the altar and recites a specific prayer after each of the tasks is performed. There is a 25-minute time limit, so the second player spends up to 25 minutes standing at that altar waiting for the first player to do his stuff, and gets to do nothing but type in a sentence into main chat 7 times during that time. What I got wrong was that I was convinced that only the first player, the one who does all the running and needs all the materials, would pass the initiation test. So I was reluctant to ask around for another player to help me with the test, and decided to create a mule character for that purpose. But once I finished the closing ceremony if the initiation to Worship with my two characters, they *both* got their test passed. Duh! Different story, instead of bothering somebody to stand around stupidly for half an hour I would actually have helped him pass his test without him needing any materials.
What else can one use a "mule" character for in A Tale in the Desert? As I mentioned, ATitD has a huge range of different activities to gather or transmute resources. Many of them are mini-games, or do in some other way require your full concentration, so doing them on two computers with two characters on two accounts isn't all that feasible. But there are some activities that are limited for example by your endurance stat: You can perform them a few times, usually 3 times, until you are tired and need to wait about a minute to fully recover and do the next 3 times. That is tedious to do with your main character, unless you manage to find another activity which you can do during a 3 clicks - wait 1 minute - 3 clicks - wait 1 minute cycle. But it is a perfect activity for a mule on a second computer, as you need only little input from time to time, while your main character is free to do more interesting stuff.
And then there is travel. In A Tale in the Desert you *can* move using the arrow keys if you set that up in the options, but the usual method of movement is to click on the place where you want to go to, and your character starts running there. While that is something that takes getting used to if you are more familiar with a classic WASD movement, there is actually one advantage to that click to move method: You can press F7 and zoom way out, then click once on the horizon, and your character will run for a while without needing any input from you, unless he runs into an obstacle on the way. The map of ATitD being so huge, using a mule to do some of your running works quite well, for example for hauling ore from a distant mine. Thus the term "mule" for a character mainly used to carry stuff for you. :) A variation of that theme is travel by teleport, which consumes "travel time" of which you only have limited amounts accumulated while offline. Using a second character effectively doubles your accumulated travel time. Or it can be used for other "offline chores", like gathering onions to feed your sheep.
So having a second character is helpful, but not to a degree where I would consider it necessary. Thus I paid for my mule for only 1 month, and won't use the second character after that. Note that this way I found out that one shouldn't use the "cancel account" function in the Billing menu for cancelling your subscription. "Cancel account" completely kicks you out of the game, and if you try to log back in you can only do it after answering affirmative to the question on whether you want to resubscribe. While that was a bit unsual and disconcerting, I didn't actually lose the rest of the month I paid for. By doing first "cancel" and than "resubscribe" I ended up back in the game, with the account still being paid for for the rest of the month, and my credit card details not on record any more, so the account will expire at the end of the month. That could have been programmed more elegantly, but the final outcome was the same as cancelling your subscription in any other game.