Oh shit! You want me to roll? (Skills tests)

Rolls are based on rolling d20s.

The GM sets a difficulty (0-5) for which the player has to roll that many successes.

Successes are determined by a roll (per d20) equal or lower than the target.

Critical success and catastrophic failure

A rolled 1 is a critical success = 2 successes.
A 20 is a catastrophic failure - bad things this way come.

The target

The target is determined by adding the relevant attribute and skill.

The dice pool

The dice pool, by default, is 2d20. This can be increased by purchasing further d20s with action points.

Dice poolBonus d20sAP cost
2d20-0
3d20+ 1d201
4d20+ 2d203
5d20+ 3d206

Perks?