Allies vs Party vs Slivers!
If you don't know what a wizard's tower is, check out the rules here:
https://magic.wizards.com/en/articles/archive/making-magic/wizards-tower-magic-format-2013-07-23
Now subtract booster packs and instead preconstruct your own pile!
Some goals I had for this particular tower:
Low budget!
I only bought cards more than a dollar if I felt like they were essential to the balance - this mostly applied to slivers. I had to forgo some more appealing cards due to the price, such as Morophon.
No shuffling!
Shuffling 200 double sleeved cards is bad enough once at the start of the game. We don't need that nonsense slowing us down, so no tutors, no evolving wilds, no rampant growth. It also makes scry a neat way to interact with your opponents draw step.
No tokens!
I want the game to avoid being bogged down and cluttered, as well as easy to transport. Only one card makes a token and those are treasures, so those can be easily marked with dice.
Embrace the uniqueness of the format!
There are lots of cards that interact with the shared graveyard, or the shared library, or have flashback, or are more interesting in multiplayer games. Which leads to some subrules...
a) Be careful of the format! Things like instant speed flashback cards are tricky when everyone casts from the same graveyard, so they are avoided. Past In Flames is very much toeing the line and may be on the cut list if it gets too tricky.
b) Continuing off of that, be careful of slivers! Many older slivers say "All slivers" instead of "your slivers," which I thought would be fun at first, but I realized very quickly it actually just makes things more complicated without adding a lot of fun. Therefore, I stuck to "your slivers" as much as possible.
Lands!
I have 13 of each full-art Theros: Beyond Death basic land. In addition, there are 4 Unclaimed Territory, 4 Prophetic Prism, 1 Gateway Plaza, and 1 of each guildgate. If I choose to expand the tower beyond 200 cards, I will add 1 more of each guildgate and a few more gate interactions for a neat little subtheme!
In the offchance you actually see this, I hope you enjoy!