Mythmere's cat may be more agile than Schrodinger's, but I don't want to leap to a conclusion.
A gang of 165 orcs is not a wave but an aggregate of particles. At any point in time, an orc horde in fact occupies a particular point in space. It moves not only at a finite speed, but at one considerably less than the speed of light.
The orc horde does not exist independently of spacetime! Assuming it's not under a spell of invisibility or the like, then looking into the Cow Palace or Madison Square Gardens establishes a fact not only about the place and time but about Rob's Orc Mob: either R.O.M. is there, or it is not.
So, the more players know about where the orc horde was not, the more that further possibilities are constrained.
It is incumbent on the DM, I think, to have a "reasonably precise" view of R.O.M.'s whereabouts. Its appearance, however sudden, must be consistent with whatever phenomena previously informed players.
Why? Because the only way to "retcon" that information is likely to be to rewind and replay so much that the encounter warranting the exercise in the first place gets shunted off to an alternate timeline.
A gang of 165 orcs is not a wave but an aggregate of particles. At any point in time, an orc horde in fact occupies a particular point in space. It moves not only at a finite speed, but at one considerably less than the speed of light.
The orc horde does not exist independently of spacetime! Assuming it's not under a spell of invisibility or the like, then looking into the Cow Palace or Madison Square Gardens establishes a fact not only about the place and time but about Rob's Orc Mob: either R.O.M. is there, or it is not.
So, the more players know about where the orc horde was not, the more that further possibilities are constrained.
It is incumbent on the DM, I think, to have a "reasonably precise" view of R.O.M.'s whereabouts. Its appearance, however sudden, must be consistent with whatever phenomena previously informed players.
Why? Because the only way to "retcon" that information is likely to be to rewind and replay so much that the encounter warranting the exercise in the first place gets shunted off to an alternate timeline.