I kind of like that the casino is just one small area that you must seek out/find as a distraction during the event after saving up slime coins for. A lot of our events feature the big bad- Tortodrones, Apocrea, Margrel, this one isn't like that and that's kind of nice. It plays well into the game and is sort of magical.

For it to really function it's going to need a unique reward like you said, possibly 4 unique rewards for the 4 different slots. Hard to obtain item reskins would be a good candidate for this, which you also mentioned so you're not like, totally off base. It's a crown sink at heart (i.e. you can use crowns!) but it also creates crowns. The trick is that newer players that can't afford to waste crowns (and need crowns for their own progression) receive crowns for free via slime coins while those of us with millions are free to dump that out for a chance at something amazing.

I guess the only thing I'd really change about the event (unless they want to go all out with it) would be to make the casino its own level. Since it is an event players are going to flip out and try to find it... and well, we already have 3ish events where you find the level segment containing the slime casino, or a room like the slime casino.. except with those it makes sense because you need to find as many cake rooms or punkin rooms as possible. With this you only need to find one casino to gamble on, then call it quits. Logically it should just be its own level that replaces say, a treasure vault on slime strata or something. Then it wouldn't even need an event, it would just kind of happen naturally every now and then. Given its nature, once every month or two for the level to spawn in the arcade would be about perfect. In the past this would have even let us go out of our way to create slime areas.

@Fangel
I don't know if this is a good idea or not... Personally I found the casinos a shitty idea in the first place, but as long as they don't interfere with my gameplay I don't care. Just keep them out of my face! ^^

@Jagglypoof
Do not. Ever! Under any surcumstanses, or in any ways replase tresure waults with thise crappy, stupid and compleately useless piece of garbage mashines! They do not in any way improve the game or game experience, and is no more than a huge waste of time, and programming time...

Weapon/Trinkets slots would certainly count as unique items! I'm all for it.

Why waste time fixing something that is useless, and don't make the game better anyways? If you want to waste time and money on being exited over nothing... Why not play a real lottery or casino? Casinos are specificly made. not to give you back what you pay for. We don't need them, and there are a lot of other usefull thing the Grey haven crew could spend their time doing(Like improving tank armour for example...).

Those ideas are nice, but there's some things to note...

1. Moving those casinos to the end of levels would be a great idea! It should save us trouble of finding them throughout the levels.

2. Yes! They should be in every Treasure Vault level! What better place to give out great rewards than in our own Treasure Vault levels? One thing, rewards won there would be double than what we could get in regular levels.

3. Rather than having limited machines that have a % of breaking & cannot be repaired, although the increased rewards are nice, how about instead there's a % chance the machine could break for 1 day, & we would not be able to use them for the rest of the day, while repairs are being made? That way, they could come back and try again. Moderation is important to counter endless gambling, even in real life.

4. I'm not sure about hard-to-obtain reskins. They're always boring.

5. My thought about such a unique reward is having new temporary multiplier pickups that grants us Knights double, triple, & even quadruple the amounts of Sparks of Lives, Crowns, Health, Fire Crystals, & even Alchemy Orbs. Items don't count to that.

6. There should be some limit to how much Crowns we can use in the Golden Coin slot machines. Using Golden Slime Coins are an exception to that, as we can spend them properly, but we must be cautious to how we will spend our Crowns in them each day. I'm thinking the limit should be 1000 Crowns, that is 200 per use, which is 5 uses. Once done, they cannot be spent more until tomorrow.

7. Different prize wheels, that's OK. Just as long as they all have the limits of how many Crowns we can spend daily. We can't go broke so quick.

8. Perhaps we could have chances of obtaining rare items in the wheels. Better to have so much to win than have little to win at all.

9. Agreed on every account. The deeper the depths, the higher our rewards should be. We should be getting lots more as we go deeper into the Clockworks.

10. Different slot machine types, that we can agree. They should be differed randomly, long as we still get something worth using them.

Moreover, I agree with those concerns of spending Crowns all willy-nilly & crazy-like, 'cause it's a reflection of real-life gambling. We need to have moderations to them.

Need gear in those slots

It's just that the Golden Slime Casino is very new to me, & I do get some points on your statements. I just don't want so many knights to spend too many Crowns to do the slot machines, & it's more or less concerning to those who want to complete their missions.

Moreover, I'm enjoying the new content we've been given!

another issue is balancing of the machines. right now it seems like the machines are balanced very closely to the breakeven point, meaning you can easily keep playing without losing too much. that shouldnt be the case though.

to properly balance the machines, you should multiply the output times its chance and sum them all up. this number should be below 200cr, so you most of the time make a loss. this is very important for my pure cr machine, but less important for the others.
for the rarities and slots, you can simply take the CE price of the items in the supply depot (not counting fire crystals, those prices are terrible) and convert their value to cr, while taking a generous conversion, like 70cr per CE. this can be set generously because even if the machine is unfairly balanced to give out more than you put in, it still drains cr from the market (but it should still not be too good). and if the rarities are bound, they cant even be sold for profit. the slots and boosts should still be unbound though.
the last machine that gives special items would be harder to balance. you could look at the current prices for varying promo items and set costs similar for the machine ones, such as making plain recolours have a chance proportional to a worth of 30kcr, while reskin gear is around a million crowns. your idea for the materials could also be implemented as the low-cost prizes here.

another thing, jackpots (even the minor ones) should always break the machine. this gives our eager gambler a moment to bask in his success and a small break for them to tell everyone and their grandmother what awesome thing they just got.

you know what? we actually never had armor reskins. kind of makes sense because costumes, but it would still be neat to have costume pieces that can also be unbound and have stats of their own. so why not release a couple different pieces?

lets see, the casino is populated by various slimes, kleptolisks, some undead and a couple devilites.
first of all, gold slime gear would be great. mercurial reskin makes sense, because it is one of the better jelly armors. normal or node style?
kleptolisk would be next, just a colour swap on the armor and a differently shaped helmet from a base chroma set. this should be a virulisk reskin.
we already have undead-themed gear, so skip that.
devilites are another interesting thing. maybe take the 2* skelly and retexture it?