Timed. Timed effects will end in a specific predetermined time, anywhere from five seconds to five days. If hit by two different timed effects, both will run at the same time.
For Example: Finther is hit by a Paralysis gas that will last five minutes. Two minutes later, he is hit by a Drain spell which also lasts five minutes. He is still paralyzed, but once the Paralysis wears off, he will be affected by the Drain for three more minutes.
You cannot have two of the same effect on you at the same time, so if you’re hit by two identical timed effects, the most recent one will always prevail.