Are there any templates or races which lower the ECL of a character with that race or template? If so, what are they? Are there any that have a minimum total Level Adjustment less than +0?
Incarnate Construct—the only true negative, −2, but still +0 total
The incarnate construct template from Savage Species turns a construct into a humanoid or giant, and reduces the LA of the construct by 2. It cannot reduce a character’s overall LA below +0, so for a construct that has less than LA +2, other templates must be applied to get the full benefit. Like dragonborn, the template is very cheesy with warforged.
Xvart—LA +0, but at some point a fan list typo’d it as −2
Xvarts from Dragon vol. 339 are sometimes claimed to have negative LA—they do not. They have LA +0, and a negative CR adjustment. There appears to have been a fan listing that put the CR adjustment as the LA and this gets repeated sometimes.
Epic Level Handbook—unadulterated garbage
Epic Level Handbook is a horrible mess, and basically unusable for any purpose, but it’s particularly poor in this case: its description of level adjustment is completely wrong and makes no sense. It suggests that ECL is LA + class level only, and then seems to kinda-sorta imply that PCs don’t actually get racial hit dice at all?
None of the monsters in Epic Level Handbook even have an LA assigned to them—not even the winterwight discussed as an example in the level adjustment section, or the worm that walks template which discusses how to make characters with it. The 3.5e update PDF for Epic Level Handbook gives an LA +7 to the mercane, but that is literally the only one.
But nonetheless, on page 156 there is a table “Monsters by Challenge Rating” which also includes an “ECL” column which indicates a number for several creatures. The number for the winterwight, for example, is 25—which matches the LA +25 that the example on page 155 used. And that is despite the fact that the winterwight has 32 HD. That means that you are, I guess, expected to deduct the 32 HD and their associated benefits from the winterwight, apply what’s left to your character along with their 1st class level, and call that a 26th-level character. It’s not, in case you were wondering.
But the real problem here is that the Epic Level Handbook doesn’t get to redefine ECL and LA—per the errata rules, this contradiction should be ruled in favor of the primary source, which is going to be the core rulebook in the case of a contradiction between a core source and a non-core source. So despite what Epic Level Handbook says, PCs do get the RHD of these creatures, and LA is then added on top of that. Untangling this mess becomes impossible. You could treat the “ECL” column of that table as in fact being the “LA” column—after all, Epic Level Handbook claimed they were the same—or you could treat it as actually the total ECL, and back-calculate an LA value for each creature—which will in many cases be negative.
Or, you could do the best thing, and throw the Epic Level Handbook in a fire. It will serve you far better providing warmth and light than it will providing you D&D 3.5e rules.
Negative character level adjustment doesn’t exist
There is definitely not any way to have a character with negative LA. If there was, it should be banned at every table.
No, not in any official product
To the best of my knowledge, while you can reduce your level adjustment in various ways (see below), there was no official D&D product which lets you reduce your Level Adjustment below +0.
IMarvinTPA's monster search, which lists most monsters (though not templates), finds no results for creatures with a level adjustment of -1 or -2. Perusing other forum threads also finds no results. Even the D&D 3.5 kobold, underpowered for level adjustment +0, is still only level adjustment +0. I can't even find any homebrew content on any of the D&D wikis which confers a negative level adjustment that can reduce below +0.
Ways to reduce level adjustment
There are several ways to reduce level adjustment, but none of them can reduce a level adjustment below +0 to actually give you negative level adjustment.
- The incarnate construct template (Savage Species), intended for use on powerful creatures like golems, has a level adjustment of -2. However, it cannot reduce your level adjustment below +0. You can't use this on a warforged to get two free character levels.
- The xvart (Dragon #339) is listed on some pages online as LA -2, but this is a typo caused by someone misreading its challenge rating entry; the actual magazine says its level adjustment is +0.
- Player's Guide to Faerun, p.190, lets you start with a level adjustment at 1st level by taking negative levels, but not below zero.
- The Reducing Level Adjustments rules from Unearthed Arcana lets you pay XP to buy off your level adjustment, but again, not below zero.
- The Savage Progressions articles provide ways to take level adjustment gradually, but again, not below zero.