Hit detection

attack box   the shape the attack searches, placed from your feet
monster box  the rectangle a monster can be hit in

targets      monsters whose box shares area with the attack box
             → put in the attack’s priority order
             → cut at its target count, 15 at most
             → minus anyone terrain hides, for attacks that check

• The white cross in every diagram is that point at your feet. The client measures every box from it, x to the right and y down.
• The rules were read out of the release client and published on the OSMS data explorer. The skill boxes drawn here are this site’s own read of the same client.

• What you see does not move the box. A longer weapon sprite, a bigger effect or a projectile that flies further changes nothing.
• Only 7 release skills that pick monsters carry a box of their own in the client; the rest use the swing’s box, the line or the cone. All 7 are in the explorer below, and weapon reach lists every box.

shared width  = min(attack.right, monster.right)
              − max(attack.left, monster.left)
shared height = min(attack.bottom, monster.bottom)
              − max(attack.top, monster.top)

candidate     = shared width > 0 and shared height > 0

• Every monster in the release uses one or more plain rectangles. The client can read a second collision format too, and no monster uses it.
• Being a candidate is not being hit. Priority, the target count and, for some attacks, terrain still decide.

targets = the first N candidates, in priority order
N       = the skill’s target count at its level, 15 at most

• N is the skill’s own target count: Rush takes 6, Savage Blow 1. No release skill asks for more than 6, so the 15 only bites on Meso Explosion CoT2: From Closed Online Test 2 (Beta 2). Not in the Public Release; kept here as a record., whose count reaches 15 at rank 30.
• Terrain comes after the cut. If a wall throws a target out, its slot stays empty, so a crowd behind a wall can eat your whole target count while the monster in the open goes untouched.

• The check line is not the arrow. It is a test the client runs once, between finding the targets and playing the attack.

• A platform blocks from above only. A line that comes up through it from underneath is let through; a line that goes down into it is stopped. Standing on a platform and shooting down at something below is stopped at your own feet.

• The animation doesn’t decide it. Arrow Rain CoT2: From Closed Online Test 2 (Beta 2). Not in the Public Release; kept here as a record., Arrow Eruption CoT2: From Closed Online Test 2 (Beta 2). Not in the Public Release; kept here as a record. and Magic Claw all look like they fly, and none of them checks.
• Skills marked CoT2: From Closed Online Test 2 (Beta 2). Not in the Public Release; kept here as a record. are third job, which only Closed Online Test 2 had. The release client still carries the rule.