|View static image|
|Number of cells||7|
|Year of discovery||Unknown|
Die hard is a 7-cell methuselah (essentially a collision between a block and the traffic light sequence) that vanishes after 130 generations, which is conjectured to be the limit for vanishing patterns of 7 or fewer cells. Note that there is no limit for higher numbers of cells, as eight cells suffice to have a glider heading towards an arbitrarily distant blinker.
Alternatively, "die hard" or "diehard" may refer to any methuselah that eventually vanishes. These are referred to as "messless methuselahs" by Catagolue and apgsearch.
For example, on January 7, 2019, a symmetric soup search run by Apple Bottom turned up a 31x31, 1340-tick diehard:
|(click above to open LifeViewer)|
As of early 2019, the longest-lasting diehard found in an asymmetric soup (and fitting inside a 16x16 bounding box) is a 1058-tick "C1" pattern found by Dave Greene on January 20, 2019.
In other rules
In HighLife, despite the instability of the traffic light sequence, the die hard still works, disappearing after 119 generations.