Imp Staff - Official Terraria Wiki

↑ Information taken from the Desktop 1.4.4.9 source code, method AI_062() in Terraria.Projectile.cs. The Imp's ai[1] is increased by 1 each tick and then has a 1/3 chance to be increased by 1 another time. Therefore, it is increased by 4/3 on average for each tick. The threshold is 90, so the average cooldown between attacks is 67.5 ticks. ↑ A tick is a time unit countable by the software. Most of Terraria's updating logic happens every tick. A tick has the length of 1/60th of a second, hence there are 60 ticks in a second and 3600 ticks in a minute.