Celebrim
Legend
Agreed, but I am talking about a situation like this
https://www.youtube.com/watch?v=gqRdT8m1Suo
Yes, you could just run through and rely on reflex saves, but that would be pretty suicidal. In this case, you really need to understand the timing pattern BEFORE you attempt the challenge.
Ok, but now if you wish to complain about me changing the scenario, I must note we've changed the scenario again and far more drastically than I changed it. In your chosen gauntlet, there is no 'jump' check needed to get from platform to platform at all. The actual pattern once they get in to it is trivially simple and requires no particular athletic ability at all - fitting for actors not known for their stunt work or physical gifts. They simply step forward just after the next obstacle flashes by, and they have several seconds to react before their prior 'platform' is subject to attack. They never have to go backward in the pattern, and they never so far as I can see have to vary their slow advance to skip forward several 'platforms'. There are barely any reflexes involved at all, and in fact I'd rate the reflex save here at about DC 0 because the windows of time they are using are rather large - grandma might not move fast enough but just about anyone else could.
Note however, with the changed scenario you still have a reflex save - albeit a trivial one. It's not at all clear that Concentration has anything to do with this new scenario either. Concentration gives you no ability to discern patterns. Concentration is not an intelligence (planning) or wisdom (perception) based skill. Concentration as it is defined in D&D is a skill of enduring physical hardship. It applies in situations where pain might otherwise distract you from performing a task correctly. It's got nothing to do with understanding traps, machines, or planning your way through an obstacle course. I suppose you might argue that it has do to with avoiding distraction or paralysis due to mental fear, which seems reasonable, but there is a different mechanic that is typically used for that - a Will save. Concentration checks by the rules aren't required in the Galaxy Quest situation. Typically, in the Galaxy Quest situation, D&D doesn't require fear checks either (though my SIPS system does, via a Heart roll, but primarily because SIPS is designed to simulate life as a small child and not life as an Action Hero).
Understanding that the pattern in the Galaxy Quest gauntlet of traps is a simple one that involves a sequential series and that the gauntlet can be navigated sequentially going forward a step at a time is a perception based or intelligence based skill. A person trained in meditation is not necessarily any better at doing it.
In the OP's original scenario, there are swinging/moving platforms that must be jumped between. Planning for or understanding the whole pattern offers no real advantage unless you intend to wait for a point in the pattern that you can jump several platforms in quick succession, which conveys no obvious advantage over waiting for the optimal moment to jump to the second platform, then waiting for the optimal moment to jump to the third, and so forth.
And actually Celebrim, this is already built in to the Rogue class as part of the Trapfinding class feature, provided they train in Disable Device.
Note that Disable Device is an intelligence (planning) based skill. So this is at least a reasonable suggestion for analyzing the pattern in a gauntlet of traps. It silo's the rogues specialty; it involves the right ability score; and the skill is at least related to the subject of the action - devices. While it is a variant use of the skill, of all the RAW skills it's probably the most relevant to understanding the pattern of attacks in a trap scenario. So, sure, I'd buy Disable Device as the skill for analyzing and predicting which squares get attacked next in a regular pattern by a device. But Disable Device is not concentration. It's also has relevance mainly in your 'Galaxy Quest' situation, and not in the OP's moving platform scenarios or any of my slightly altered moving platform scenarios that I've used to illustrate that the OP's scenario is just one case of a general Reflex save pattern.
You are seeking to lower the overall DC of your task by concentrating beforehand to optimize your timing.
This is a very 4e skill challenge approach. Attempting to justify that your unrelated skill gives you a 'success' of some sort in getting through the gauntlet is fine if this is a skill challenge, but it's not, and in any event doesn't address the OP's question of "How do you measure "Timing""? In 3e, matters of timing are matters of a Reflex save.