Characteristic and skill tests are made using 2d10 before adding and/or subtracting any relevant modifier.
A 2 results in a critical failure - you fail no matter how high your Characteristic/Skill values. Survive or Die Wide open
A 20 results in a critical success - you succeed no matter the test’s difficulty Survive or Die Critical hit
Advantage
Disadvantage
Other dice rolls can involve the following dices : d4, d6, d8, d10, d12.
When the result of a dice throw is a fractional number, it is rounded down.