Nemesis: Lockdown · Board game rules
If i allready had 2 light wounds and i get 2 light wounds from an attack, do i get a serious wound and then the light wound tracker resets or does it go to 1 light wound?
You will suffer a Serious Wound immediately when the third Light Wound is reached, which discards your Light Wound marker. The remaining Light Wound will then place a marker in the upper slot, leaving you with 1 Light Wound plus the new Serious Wound.
Light Wounds are resolved individually, meaning if you gain multiple at once, you process them one after another. When you already have 2 Light Wounds (marker in the second slot) and gain a third, the marker moves to the third position. According to the rules, "If the marker reaches the third position, discard the marker and the Character suffers a Serious Wound." This triggers the Serious Wound condition and removes the marker from the track. (Page 23: Light Wounds)
Since the marker is discarded, the Light Wound track is considered empty for the purpose of the next wound. When you suffer the second Light Wound from your attack, the rule states, "if there isn't a Status marker on their Wound track, place one in the upper slot." Therefore, this final Light Wound will place a marker back in the first position, resulting in you having 1 Light Wound and 1 Serious Wound remaining. (Page 23: Light Wounds)