scmJS docs

Set Deaths

Changes the player's death count for the unit type. It is how maps keep numbers: nothing but Set Deaths and units dying changes a death count, so the counts of unit types a map never uses can hold anything.

Add past 4,294,967,295 wraps around to 0, and Subtract stops at 0.

Action 45 · Set Deaths(Player, Unit, Modifier, Amount);

Argument Takes Stored in the action
Player a player or group bytes 16–19
Unit a unit type, or one of the unit classes bytes 24–25
Modifier Set To, Add or Subtract byte 27
Amount a whole number, 0 to 4,294,967,295 bytes 20–23
Set Deaths("Current Player", "Cave (Unused)", Add, 1);