Proper Laboratory Attire — ruling 1

Protection from die rolls means the equipped creature can’t be dealt damage by, equipped or enchanted by, blocked by, or targeted by anything that allows or requires someone to roll a die. This includes any kind of dice, not just six-sided dice. This also includes anything that allows you to reroll a die.

Proper Laboratory Attire — ruling 2

The equipped creature won’t have protection from anything that cares about the results of dice without allowing or requiring someone to roll a die, such as Snickering Squirrel.

Proper Laboratory Attire : règles, fonctionnement et interactions (MTG)

Proper Laboratory Attire is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Equipped creature gets +2/+1 and has protection from die rolls. (Nothing that lets a player roll a die can block, target, deal damage to, or attach to equipped creature.) Equip

How it works : Proper Laboratory Attire

Original English text — Wizards of the Coast / Scryfall

#1January 19, 2018· Wizards of the Coast
Protection from die rolls means the equipped creature can’t be dealt damage by, equipped or enchanted by, blocked by, or targeted by anything that allows or requires someone to roll a die. This includes any kind of dice, not just six-sided dice. This also includes anything that allows you to reroll a die.
No other card is named in this ruling.
#2January 19, 2018· Wizards of the Coast
The equipped creature won’t have protection from anything that cares about the results of dice without allowing or requiring someone to roll a die, such as Snickering Squirrel.
No other card is named in this ruling.