Thopter Spy Network is good, but be careful to read it correctly! It triggers whenever "one or more artifact creatures deal damage to an opponent," NOT once for each creature dealing damage.
Author: bimmerbot
Liliana doesn’t transform if she dies at the same time as other creatures.
Because of the "if you do" clause, Liliana's trigger won't do anything unless it's able to exile her from the battlefield. If she's already in the graveyard, it can't find her to exile her, so you won't get a transformed planeswalker and you won't get a zombie.
Ugin’s -X ability vs. transformed planeswalkers
A card with no mana cost has CMC of 0, which includes the back face of double-faced cards like the new Planeswalkers from Magic Origins. They also have a color from their color indicator, so they will be exiled by Ugin's -X ability with any value chosen!
Starfield of Nyx and enchantment creatures.
Oh, . It, comboed with , was the bane of many judges’ and rules gurus’ existence. Even though things have been figured out for a while now (we even have a Gatherer ruling to cover it). But now they’ve brought back “Opalescence” in the form of . It’s not that bad this time, but there […]
If Kothophed dies while enchanted by an opponent’s aura, it won’t trigger for the aura.
When a creature dies while it has an aura attached to it, the auras don't technically move to the graveyard with the creature. They wait until they're on the battlefield unattached to be put in the graveyard, immediately AFTER the creature dies. This is rarely relevant, but today you can learn when it matters!
Blocking with mana creatures against Archangel of Tithes.
It's possible to block using a mana creature (e.g., Elvish Mystic) and tap that creature to pay the cost for Archangel of Tithes!
You should kill Polukranos before it becomes monstrous, not in response to the trigger.
Polukranos has an activated ability that makes it monstrous, and a triggered ability that triggers when it becomes monstrous. Kill it before you get to the second part to avoid having it deal damage.
Hangarback Walker vs. Eidolon of the Great Revel and Disdainful Stroke
The X's in a spells cost are counted as having the value chosen for it while that spell is on the stack. As such, Hangarback Walker for X=1 means a CMC of 1+1=2, and it would trigger Eidolon, while X=2 means CMC 2+2=4 to evade Eidolon's trigger.
Tragic Arrogance can choose one card for multiple types.
Tragic Arrogance doesn't ask you to choose separate permanents for each card type, so you can maximize value by choosing a single card twice for your opponents.