ACE Anti-Cheat System is a passive item in neverbirth, a mod for The Binding of Isaac.

While heldDoubles incoming damage to the holder.

While any character holds this item, killing an eligible ordinary enemy after one counted damage event triggers 5 real seconds of severe stuttering and room slowdown.

The third such kill in the same room kills every living character.

The following tags are applied to this item:

The kill counter is shared by the entire team and does not require the holder to deliver the killing blow.

Extra copies do not increase the damage multiplier or lower the three-kill threshold.

Bosses, minibosses, friendly enemies, invulnerable or inactive enemies, knockback-immune enemies, and the main body of a segmented enemy are excluded.

Ordinary summons and split children can count.

One-hit detection counts observed accepted damage events while the audit is active.

Several damage requests in the same frame can affect the result.

Another qualifying kill restarts the five-second stutter period.

Entering another room resets the kill counter; an active stutter period can carry into the new room until its real-time timer ends.

Losing the final copy or leaving and continuing the game resets the audit state.

The published EID calls the effect a 3-FPS-style stutter.

The actual effect does not guarantee an exact frame rate.

The third-kill penalty kills the team rather than closing the game.

• Download neverbirth from the Steam Workshop.