I'm pretty sure that what the math suggests is what happens in game. Anecdote isn't evidence, but it sure SEEMS like negative defense behaves as to-hit buffs. And it would make sense for it to behave that way. Since we have the Achilles' Heel proc, I know that resistance debuffs work that way.
"That's because Werner can't do maths." - BunnyAnomaly
"Four hours in, and I was no longer making mistakes, no longer detoggling. I was a machine." - Werner
Videos of Other Stupid Scrapper Tricks
Defense debuffs work on plenty of mobs that have no defense (read: 0%). Stands to reason it would work just as well on players.
Even level minion attacking you (assuming you def is 0) would have a 50% chance to hit. If you get debuffed for -10% defense they would then have a 60% chance to hit.
OK, while debuffed below 0% defense for a few minutes against some Cimerorans, Herostats says they hit me 80% of the time with Slash and 66.67% with Slice. Probably not a long enough test to count as proof, but certainly indicative that everything is functioning as expected.
"That's because Werner can't do maths." - BunnyAnomaly
"Four hours in, and I was no longer making mistakes, no longer detoggling. I was a machine." - Werner
Videos of Other Stupid Scrapper Tricks
Hmm, interesting results. I'll try testing that later on a couple toons myself to see if I can produce similar results.
[ QUOTE ]
Every now and then, I see that my defenses get buffed by the enemy on a regular basis.
[/ QUOTE ]
exactly which enemies are buffing you ?
[ QUOTE ]
[ QUOTE ]
Every now and then, I see that my defenses get buffed by the enemy on a regular basis.
[/ QUOTE ]
exactly which enemies are buffing you ?
[/ QUOTE ]
Well I think he his talking about his defense being Debuffing, I don't know but the hole Negative defense question gives it away. 
"All right, they're on our left, they're on our right, they're in front of us, they're behind us...they can't get away this time"- Chesty Puller US Marine Corps
Yeah, you miss two letters and your whole message can get borked. Me is dum.
Every now and then, I see that my defenses get buffed by the enemy on a regular basis. I was just reviewing Arcanaville's defense post, but it doesn't say anything specifically about about defense that gets debuffed to the point where it is in negative values.
By the advanced formula, the math would suggest that enough defense debuffs could translate to effective "To Hit buffs" (mathematically speaking). So is this true in practice, or does it simply render defense as 0% (though also rendering any additional defense buffs ineffective until it can actually overcome the debuffs themselves) with no net To Hit "bonus?"