The Tick Save Resist Floor (Charm, Root, Blind, Fear)
As I mentioned previously, spells with tick save throws also have their own resist floor just for the tick saves, which is 5. This or the level difference floor is used for these spells, whichever is higher. I mention the existence of this floor in another older thread which I had discovered via other means but it's also clearly seen in these decompiles. This floor includes fear and blind which I previously was not sure of. This floor never changed and is still 5 on Live servers, except for fear spells which seem to have lost this floor at some point. (perhaps blind as well but I didn't check)
The level difference floor which was removed in the September 2002 patch had huge implications for spells with tick saves.
These spells were simply much worse before September 4 2002 and they broke upwards of four times as frequently as they do using the later era resist logic. Since the rolls were 0-99, a floor of 10 is about the equivalent to a floor of 20 in the post Sept 2002 resist logic. These floors are set just above where the roll is done in the logic so there is no doubt when looking at the decompile how the code flowed.
Tick saves however get a +4 caster level to them, so the 10 MR floor would begin at -6 levels instead of -10 levels difference. This is likely part of why tick saves have this +4 level mod applied to them, so that the 10 resist floor isn't applied to as many dark blues. This +4 would have made a level 43 mob the ideal long-term pet for a level 50 enchanter player. If a level 50 player tried to charm planar mobs, fire/ice giants, or even a higher level bok ghoul knight using the old resist logic, the average duration would have been just 17 ticks because of the 10 resist floor and the break chance per tick would have been four times more frequent compared to the PoP era logic. On the TAKP and Quarm servers, which have PoP era resist logic, this average is 60 ticks assuming they were MR debuffed to the 5 MR tick floor. (using Allure)
Tick saves are
not checked every single tick however. They have a preliminary roll done each tick that must succeed before a resist check is done. This preliminary roll is 50% for charm and 75% for root, blind and fear spells. (meaning most ticks
will do resist checks for these three) As far as I am aware this has never changed but I can't be certain. These were not found in the decompiles and were told to me by an unnamed source, however the lull break early preliminary roll was found in the clients and this is a 1 in 4 roll like the others, minus charm. Lulls have a tick save throw as well but it doesn't have a floor because this spell line has MR overrides which I explain in a later section.
Lastly the charisma stat
did apply to charm tick saves in classic era, according to the decompiles, and it was not limited to enchanters. This was seemingly removed in the September 4 2002 revamp, as some 2003 charm data I found showed no benefit from CHA. (see my other thread) Perhaps because they massively buffed charm at the same time so this removal was a small counter-balance. Enchanters didn't need to debuff charm pets in classic to extend durations in most cases. For more details on tick saves, check my dedicated thread about it.
Tick Resist Floor Evidence Not From Decompiles
I also found an old April 2001 Casters Realm thread titled
"CHA and Charm - A numerical study at last" which had some charm duration tests in it. This kind of artifact is as rare as it is valuable and offers compelling evidence for how EQ used to be. The thread can be found here:
https://web.archive.org/web/20010513...04438&go=older
This enchanter was trying to determine if charisma made charms last longer. I can say that on Live servers right now, it does not. But the decompiles of the Kunark clients
do show charisma lowering MR on tick saves, but not under the floors. So apparently charisma used to make charm last longer if the target's MR was not already at the MR floor, and this would agree with older Sony dev comments regarding CHA and charm.
His first two tests (at differing CHA amounts) were on an exp giving green con (so almost dark blue) seafury cyclops NPCs in OOT as a level 58. This NPC's MR is 35 and the level mod in this case is -40, so without a floor the MR would be 0. Both his tests would have been at the MR floor of 5 since charm has a floor of 5 and an NPC of that level relative to him would also be 5, meaning charisma would not have been a factor. The average durations for both tests ended up at 26 ticks using a 70 tick max spell, and combined were 50 charms. This agrees with a 5 MR floor at 0-99 scale with a 50% preliminary roll, which in my simulations results in 28.5 ticks average duration. For comparison, the current average duration for Boltran's at the MR floor on TAKP or Quarm is 43 ticks in this scenario.
This guy did more tests after his cyclops tests, and this time on Ssolet Dnaas in Warsliks Woods. This NPC is permarooted which makes doing tests much easier. He did four sets of 25 casts at two different CHA levels and two of the sets were with Resist Magic on the NPC. Since tick saves get a +4 levels to the caster in the algorithm, this would make the MR floor on this mob also 5 in the tests without resist magic. The results also matched the simulations as both tests at two different charisma levels (46 charms) added together ended up about 26.5 ticks average duration.
I tried to go through the limited pre-Sept 2002 logs I have to see if they had useable charm data and they do not. But they do have useable root data. I was able to verify (with high but not absolute certainty) that roots using the old resist system had the same preliminary roll (75%) and the break rates with a 5 MR floor were as expected. You can see this in the tipa16384 archive: the Etha log is of a druid character and she was killing haunted seachests in Cobalt Scar which is always level 40 and has a typical MR of 35. The average duration of a 30 tick root was 15.78 ticks in a sample of 27 when selecting only the first roots cast on the NPCs to remove bias. Simulated root average duration is 16.37 ticks. (using a 0-99 resist roll) I checked a second log that I obtained from a submission by a TAKP player and his 2001 log also agreed with 75%/5.