Originally Posted by
Imnick
While ignite only displays as one DoT effect, behind the scenes the game keeps track of how many times ignite was procced and the damage "rolls", so it is actually effectively keeping track of one DoT for every time that you crit so it is only ever 40% of the damage of your crits rather than a constantly increasing total.
If you crit again before the two seconds that have to pass before the first ignite tick, the timer is reset back to 0 and ignite will not tick but the damage is stored, if you keep doing this over and over again (through obscene luck) then the ignite will tick for an extreme amount of damage when you finally allow it to tick, although this damage will then fall off as normal. This is the key part here, getting two or more crits less than two seconds apart drives the damage of the next tick higher and higher by not allowing the DoT to actually deal any damage.
This still only delivers 40% of the total damage of all the crits you did, so doesn't increase your overall damage in any way on its own because it is simply storing the damage to be applied in one go rather than over a period of time, but as Combustion uses the current DPS of ignite then using Combustion at such a time will mean that it will do massive amounts of damage. This is the secret to making the very high combustion damage amounts you may have seen on world of logs.