I was wanting to add baddies to my building but in a controlled fashion and won't despawn. This is what I came up with but since I'm new I'm not sure if it's going to work. I have a feeling redstone will be involved and anyone that knows me knows I don't do redstone so this is a really hard project for me and I really don't want to start digging up my floors and such if this won't work to begin with. Sorry if the picture is large I didn't know how to make it smaller >.>

It could but, are the mobs going to be pushed up by the piston?

yes and no.

Mobs are 2 blocks high. Pistons can only move things 1 block away. Yes, you can push 13 blocks or whatever, but for your needs you would require several pistons.

Your dark room would have to be at least 2 blocks high, possibly 3 to allow creepers to bounce around. you would need some method of pushing the mob onto the piston, which can be done with water. the problem is you want the mob to be pushed up inside your room. without chaining pistons together to push pistons, the best you'd get is the mob being half inside your room, and half below.

If you chain a few pistons together (tricky but it can be done) you would need probably 2. The first piston pushes the mob half way up into the room, the next piston pushes that extended piston up another block bringing the mob fully into the room.

A much simpler, but uglier, method would be instead of a room below, you build the rooms onto the sides of the club. you build it much like I make my zombie pigmen spawner, so there is no space for them to spawn UNTIL you press a button, which would pull some pistons back, allow mobs to spawn and fall into the water which would push them up against the glass windows you'd place inside the club.

I'll work on a few methods and make some prototypes at my place

I'm not sure a piston can push another piston or piston head, you could make an elevator of sorts to push them up but that would be buggy, someone else made a piston elevator and you have a pretty good chance of falling through the block when it's pushed up.

Thanks guys, I kinda realized it would only push them halfway out with one piston. Right now I have a headache so I don't really feel like thinking about it but I'll consider my options later and I appreciate your input.

You can indeed push pistons with pistons, but there is a catch.

You can use a sticky piston to push a normal piston up, which completes the circuit to extend the normal piston. The trick is, unless you time it correctly, it will not reset as you can not push/pull and extended piston. You will need a delay timer much like the super fast elevator, that ensures the pistons power down in the correct order.

I've made a sample sequencer that has two input buttons. InputA turns outputA on then outputB on. Input2 shuts down both outputs in order Output B then OutputA.

The more pistons required makes that circuit immensely more complicated and large.

honestly, the best way to do this is to create a solid room around the mob spawner (5 block radius for spawning) and have 1 area attached to pistons so when you press a button, the pistons pull back, create enough space for mobs to spawn, then closes behind them. The mobs since they are hostile, don't need any special blocks to spawn, a drop to a water path would work exactly like my zombie pigment machine at my house.

The only problem with that design is the spawners have to be above your house, or built into the walls high enough to let the water push them up against some glass. Actually, there is 2 problems. you can't be sure only 1 mob will spawn, you might get a few crammed in there.

I don't really care how many spawn, it's just that only one will fit in the glass box I make. If the other one gets stuck somewhere that's his problem