Truss, Chief Engineer — ruling 1

Truss’s last ability affects a single number or number word on the spell or permanent. It can be anything—power, toughness, something in rules text, the name of a card (Four Wishes, anyone?), collector number, and so on. Mark says you can even change the copyright date, but don’t tell the lawyers.

Truss, Chief Engineer — ruling 2

Note that you’re changing numbers, not digits. For example, if you remove two hack counters from Truss, you could change 10 to 12 or 8. You couldn’t change it to 30.

Truss, Chief Engineer — ruling 3

Indefinite articles such as “a” in “draw a card” aren’t number words and can’t be modified.

Truss, Chief Engineer — ruling 4

You can’t change any instance of X.

Truss, Chief Engineer — ruling 5

You can change the numeral inside of a mana symbol, but you can’t modify the cost of a spell in time to pay less for it. It must already be on the stack to be a valid target for Truss’s ability.

Truss, Chief Engineer — ruling 6

You can change the number of dice rolled for an effect only if the original instruction included a number word to describe how many dice to roll. You can’t change the “a” in “roll a six-sided die,” but you could change the “two” in “roll two six-sided dice.”

Truss, Chief Engineer — ruling 7

You can change the number of sides on a die. If you don’t have any thirteen-sided dice handy, you can use other dice to simulate the rolls.

Truss, Chief Engineer — ruling 8

You can’t use Truss’s last ability to change the 1 in Truss’s last ability to a 0. Nice try though.

Truss, Chief Engineer : règles, fonctionnement et interactions (MTG)

Truss, Chief Engineer 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

Whenever Truss, Chief Engineer enters or another creature dies, put a hack counter on Truss. , , Remove X hack counters from Truss: Add or subtract X from a number or number word on target spell or permanent until end of turn. This effect can't reduce a number below 1 or a number word below one.

How it works : Truss, Chief Engineer

Original English text — Wizards of the Coast / Scryfall

#1October 7, 2022· Wizards of the Coast
Truss’s last ability affects a single number or number word on the spell or permanent. It can be anything—power, toughness, something in rules text, the name of a card (Four Wishes, anyone?), collector number, and so on. Mark says you can even change the copyright date, but don’t tell the lawyers.
No other card is named in this ruling.
#2October 7, 2022· Wizards of the Coast
Note that you’re changing numbers, not digits. For example, if you remove two hack counters from Truss, you could change 10 to 12 or 8. You couldn’t change it to 30.
No other card is named in this ruling.
#3October 7, 2022· Wizards of the Coast
Indefinite articles such as “a” in “draw a card” aren’t number words and can’t be modified.
No other card is named in this ruling.
#4October 7, 2022· Wizards of the Coast
You can’t change any instance of X.
No other card is named in this ruling.
#5October 7, 2022· Wizards of the Coast
You can change the numeral inside of a mana symbol, but you can’t modify the cost of a spell in time to pay less for it. It must already be on the stack to be a valid target for Truss’s ability.
No other card is named in this ruling.
#6October 7, 2022· Wizards of the Coast
You can change the number of dice rolled for an effect only if the original instruction included a number word to describe how many dice to roll. You can’t change the “a” in “roll a six-sided die,” but you could change the “two” in “roll two six-sided dice.”
No other card is named in this ruling.
#7October 7, 2022· Wizards of the Coast
You can change the number of sides on a die. If you don’t have any thirteen-sided dice handy, you can use other dice to simulate the rolls.
No other card is named in this ruling.
#8October 7, 2022· Wizards of the Coast
You can’t use Truss’s last ability to change the 1 in Truss’s last ability to a 0. Nice try though.
No other card is named in this ruling.