What theBlackDragon is trying to explain is that seeding can be handled in a way where time is not factored into determining the outcome.
Time is not factored into seeding *DIRECTLY*.
However the "save the seed" solution only works when the RNG is only used for timing-independent actions.
Eg. take the following situations:
--- Case A ---
1) You load your savegame and load the random seed.
2) You immediately (as quickly as possible) open the chest, the contents of the chest are deterministic, as in reloading the same game with the same seed will yield the same output.
--- Case B ---
1) You load your savegame and load the random seed.
2) Wait for some time; during this time other game events will occur: NPCs start doing other actions, go wandering, do idle anims, etc. The game answers the NPC's "what should I do?" question (at least partially) by getting numbers from the RNG; thus simply by waiting and letting the game's systems work the RNG state is changed!
3) You open the chest, and the (now different) state yields different loot; if you then reloaded and waited exactly the same amount of time in step 2) you would (theoretically) get the same result every time; however even a millisecond of difference may yield different outcomes.
Edit: So its not the passing of time itself that changes your seed, but the actions that take place during that time.
Got it?
