When someone becomes invisible (PC or monster), I replace the mini with a glass bead. This is usually a fairly strong reminder that the creature is invisible. And I'm pretty good at looking at the board and ignoring the glass beads when making decisions.
If someone becomes hidden using cover, I don't replace the mini. I leave it where it's at, because a monster lurking around a corner, is no longer lurking once a character turns the corner. When you lose cover, you lose the hidden condition.
When someone uses total concealment to become hidden, like with drow darkness, I will again typically replace the mini with a glass bead.
The way I play lurkers is to almost always start them off the map. They might drop from a whole in the ceiling, climb up the ledge of a cliff, fly in out of a dark corner, or pop out of a barrel. And depending on the encounter, this could happen in the beginning of an encounter, or a couple rounds into the encounter.
Also my lurker design usually allows them scary action economy on their first turn after they reveal themselves, especially if they are primarily melee creatures (though I tend to like giving them something they can do at range). They are usually fast. They usually have a limited use ability that lets them move or shift X squares and attack at any point. And they usually have a minor action encounter power that will be useful to them in that first round.
For instance, if I was designing a lurker Drider, his first turn might go something like move action to move/climb 8, standard action to Paralytic Grasp, deal limited expression damage, daze, grab, and shift 3 squares with the grabbed creature, minor action to pop darkness.
Lurkers need long strings of actions to feel like a lurker, and to feel like they are doing their job. If you are not opposed to giving action points to standard creatures, giving the occasional action point to a lurker (maybe they can use only to take an extra move action) can also help make them feel more lurkery.
Also worth noting, lurkers often need the right terrain elements to function. You can have a choker hiding under a balcony on a shadowy street, a crocodile hiding among driftwood in a murky river, or a darkmantle hiding among stalactites in a cavern. It's hard to use a lurker just for the sake of using a lurker. It needs to be designed as part of the encounter.
If someone becomes hidden using cover, I don't replace the mini. I leave it where it's at, because a monster lurking around a corner, is no longer lurking once a character turns the corner. When you lose cover, you lose the hidden condition.
When someone uses total concealment to become hidden, like with drow darkness, I will again typically replace the mini with a glass bead.
The way I play lurkers is to almost always start them off the map. They might drop from a whole in the ceiling, climb up the ledge of a cliff, fly in out of a dark corner, or pop out of a barrel. And depending on the encounter, this could happen in the beginning of an encounter, or a couple rounds into the encounter.
Also my lurker design usually allows them scary action economy on their first turn after they reveal themselves, especially if they are primarily melee creatures (though I tend to like giving them something they can do at range). They are usually fast. They usually have a limited use ability that lets them move or shift X squares and attack at any point. And they usually have a minor action encounter power that will be useful to them in that first round.
For instance, if I was designing a lurker Drider, his first turn might go something like move action to move/climb 8, standard action to Paralytic Grasp, deal limited expression damage, daze, grab, and shift 3 squares with the grabbed creature, minor action to pop darkness.
Lurkers need long strings of actions to feel like a lurker, and to feel like they are doing their job. If you are not opposed to giving action points to standard creatures, giving the occasional action point to a lurker (maybe they can use only to take an extra move action) can also help make them feel more lurkery.
Also worth noting, lurkers often need the right terrain elements to function. You can have a choker hiding under a balcony on a shadowy street, a crocodile hiding among driftwood in a murky river, or a darkmantle hiding among stalactites in a cavern. It's hard to use a lurker just for the sake of using a lurker. It needs to be designed as part of the encounter.
