My biggest problem with timed missions is not knowing one's coming. Finish your mish, talk to your contact before logging off, pick up a mission for next time, oops!
Make sure it's very clear to players beforehand.
Arc 55669 - Tales of the PPD: One Hell of a Deal (video trailer)
Arc 64511 - The Wrecking Ball
Arc 1745 - The Trouble With Trimbles
Arc 302901 - HappyCorpse
I have no problem with timed missions as long as:
1: I know in advance they are coming. This means "You have 30 minutes to complete this mission" BEFORE I accept. It can be part of the contact's dialogue and delivered in-character, but in that case it should be colored to stand out as a warning.
2: The time limit is sufficient to complete the mission, provided I make a reasonable attempt to do so. Don't pull a Tina and hand out 10 minute timed missions. If your intent in doing this is to force failure, well most of the time I don't fail Tina's mission either, so it likely won't work. Setting a short timer to force the player to hurry is very very tricky to pull off, and even if you do it well some people will still be annoyed.
3: There's a story reason for it.
4: They don't contain required captives or allies until that bug is fixed.
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Arc ID#161629 Freaks, Geeks, and Men in Black
Arc ID#431270 Until the End of the World
In MA? Timed missions are mostly irrelevant. If you can't play through from start to finish in one setting, you can always revisit them. If you're called away to join another team while playing MA, the only way you can do that is by abandoning the arc anyways; and then again, you can revisit it if interested.
Those things are only problems in dev content. Use them if you want to.
<《 New Colchis / Guides / Mission Architect 》>
"At what point do we say, 'You're mucking with our myths'?" - Harlan Ellison
In the future I will be working on an arc with several timed missions. My question is what problems do most have with timed missions? Some things may be unavoidable but I'm at least trying to survey people here.
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Mission Architect Handyman