Is it an automatic crit if I hit with an extended threat range?

Question

In 13th Age, like most D20 variants, you can have items or abilities that improve your crit range. However, in 13th Age, a natural 20 is a automatic crit hit (if I am not mistaken, you do not need to check if you hit). What is unclear to me if say I have +2 Crit Range (18-20), is it an automatic hit if I roll a 18, or do I is that just a threat and I need to roll to see if I hit?

Updated with the rules (pg 196 of the Escalation V6 version)

Every attack roll that is a natural 20 is a crit ('critical hit') for double damage.

And that's all it says. Here's the part on crit range:

Each point of improvement in crit range drops the number needed to score a critical hit by 1.

Answer 1

In dnd-3.5e you threaten a critical hit on a natural roll within your threat range, and it needs to be confirmed to become an actual critical hit by re-rolling the attack die (the "critical roll") and scoring a hit. (d20 SRD)

In 13th-age, per your citations, you have a crit range instead, and you automatically score a critical hit on a natural roll within this range. There is no need to confirm.

In your case, if you roll a natural 18 on an attack with a weapon with an 18-20 crit range, you may roll for double damage.

Answer 2

A critical double damage (pg 167 core book). However, I don't see anything that says that all criticals are automatic hits. By a strict reading, this could lead to a case with an expanded crit range and a hard to hit opponent where a roll could be a critical but also a miss. So it would in that case double the miss damage.

With a less strict reading, the rules call out a 20 as a "critical hit", and the rules do imply some familiarity with other d20 games for basic concepts. Having any critical as a hit would be a defendable position. This could be supported that while there are rules for 20 as auto-success for skills (something not true in some popular d20 games), there are no rules that say that a 20 attack is an auto-hit, just an assumption that it is.