The Tally Counter is an informational accessory that displays how many monsters have been killed. It is one of the three parts necessary to make the R.E.K. 3000, with the others being the Lifeform Analyzer, and the Radar, and as such is a required ingredient in making the Cell Phone. When equipped or left in one's inventory, the Tally Counter will first display "Kill count unavailable" underneath the map/health area. After an enemy has been attacked, the text will display how many times that enemy has ever been killed by players in that world. The kill count will only display the last enemy struck by you or your minions. It will count deaths from world creation rather than from when it was equipped. It can be very useful when trying to acquire a specific monster banner, which drop in increments of 50.
It has a 1/100 (1%) chance of being dropped from Angry Bones, Cursed Skulls, and Dark Casters, all of which are found in the Dungeon.
- Baby Slimes don't have a kill count, and if player kills one, the Tally Counter will say "Kill count unavailable".
- Each enemy's kill count is kept track of even before a Tally Counter is acquired.
- This device works based on the world's kill count of each enemy, not the individual character's. This can be observed when travelling to a different world, as well as during multiplayer; each kill counts towards the total.
- Enemies without a respective banner, such as Bosses, do not have a kill count, and the Tally Counter will instead display that no kill count is available.
- Certain Hardmode versions of pre-Hardmode enemies do not have a kill count, and will instead share the kill count and banner of their pre-Hardmode counterpart.