To get rich, of course. The scariest minions can drop para rings , Dr. Terrible is guaranteed to drop a wis potion for 2 players, while the Horrific Creation is guaranteed to drop a defense potion for 2 players, along with both having a chance to drop some pretty decent gear. However, the main reason to go to a lab is to get pieces of an extremely powerful sorcerer set, with a scepter that is incredibly powerful and relatively uncommon. All the pieces of this set drop in white bags except for the ring, which is a common drop from Dr. Terrible and Horrific Creation in a cyan bag. Either way, each of the pieces of this set has its own purpose, and experimental ring is a good all-rounder ring. Other rare items found here are the Grotesque Scepter and the Horrific Claws, both part of the Horrific Sorcerer ST Set.
Navigating through this dungeon is rather simple. Watch out for the confuse-bots, don’t stand next to the big enforcer bots, don’t shoot at the mini-Horrific Creations until all the green abominations are dead (unless you are a maxed character that is capable of dealing damage past the healing), and be wary of the exploding bots. Try to clear every single room of the Tesla coils before you go to fight the boss - when all of them are destroyed, you are allowed to fight the Horrific Creation, which drops defense potions, as well as the Conducting Wand and Experimental Ring.
When you clear a room also shoot every single white box - , these are the Tesla coils.
If you destroy every single one in the dungeon you will open the secret room where the second boss is. Once you have done all that you are ready to fight the Boss(es). There are two other things you should know. Firstly, that the green pools turn you into an animal which makes it so that you get stunned, but it also grants the “speedy” status effect (while an animal you can still use abilities, making this state good for an unmaxed priest who just wants to help out); the blue pools revert you to human form. Secondly, in every Mad Lab there is an acid room that contains a random design chosen from an existing pool of layouts.. You have to dodge confusion shots and get through the room with out falling into the acid, which is just slightly weaker lava. This room must be passed in order to reach the boss. This characteristic can be used to a navigational advantage if one simply wants to finish the dungeon.
These are dangerous due to their massive damage output, combined with the Mini Bots they spawn when they die. These guys shoot two different shotguns, a long range one dealing 150 per shot, and a short range one dealing 60 per shot. When they die they spawn 1-4 Mini Bots to fight, these Mini Bots just might confuse you right into another vengeful Enforcer Bot.
These are probably the most intimidating monster in the dungeon. These creatures, along with having twice the health of a Medusa, can deal increasing damage as you attempt to destroy them. As they are damaged they increase in size, which proportionately increases the size the bullets are and damage the bullets deal. The easiest way to pass by them is to avoid dealing damage to them, as their initial damage output is very low, especially to a melee class with a decent level of defense.
These little jerks are everywhere and seem to know when you are focused on a big enemy, because that is when they strike. Alone these monsters are worthless but when you are fighting something that can insta-kill you in a 3 short hits, I suggest you be on the look out for pink, as their shots will confuse you for a short duration causing momentary disorientation.
Fighting Dr. Terrible is pretty straightforward - just shoot at him when he’s vulnerable and shoot his minions as they appear (it probably won’t get to this phase with sufficient DPS) if you feel you need to (especially if he spawns those mini bots). During Terrible’s vulnerable phase, three of the four coils in the room will spawn gaseous shots that do 200 damage each. If you stay in between, as close to the center, of these coils, you’ll be out of range of these gas shots. Terrible himself doesn’t have a direct shot attack, so your only real concern is to avoid the two types of “grenades” he throws (a bomb which explodes into gas after about a second and a shot tower). Both of these can be disposed of without being a real threat if you have good DPS. After a while he will retreat into a “bubble” in the center of the room where he is safe from harm. During this phase, he will spawn minions (excluding the Crusher and Enforcer) from four cages on the left/right most edges of the room. After a while, he leaves his safety bubble, vulnerable to attack, and his attack cycle repeats from there.
This boss is the most powerful, most damaging boss ever (in sheer numbers anyways) and he is absolutely invincible. The only way to get him to be vulnerable is to get him to walk into the green acid. Your means of doing that is to play bait and trick the beast into the acid. It is best if the baiting player is the closest to the Creation, as he leaps toward the closest player. Fast or healing classes are best as bait, as they can quickly dodge the Creation’s attack as they land or heal if they get hit too many times, respectively. When entering the Horrific Creation’s little kennel, everyone who is not bait should immediately go into the corners on the left. While the bait is going to work, be ready at whatever pool of acid he is working on, ready to heal, boost, or otherwise fire at the boss. If you are the bait, it helps to enter the acid for the speed boost. Stay in the middle of the acid but move around to both lure the boss in and avoid that lovely slowing shotgun he does when he lands. The only downside to this strategy would be the fact that you won’t be able to attack right away, but this is probably the easiest way to lure the boss into the acid. As soon as he touches the green acid, run to the Blue acid pool (if necessary) and do your damage. When the Horrific Creation gets to half of his health, he will not immediately go into the chase phase after curing himself, he will now start to shoot at people once before he goes to chase, if he doesn’t see anyone he can land on after he shoots at people then he will go back to shooting them again, and there are 15 shots total every time he does that. As the bait, you will have time to circle him a couple of times or otherwise lure his shots and then go back into the acid to lure him in there.
There is a rumor saying that if you destroy the tables you may find in some rooms, you will receive a greater or lesser amount of loot. These rumors have not been confirmed, and as the burden of proof is upon those making a claim, one should assume that they do not affect drop rates in any way, and that any “effect” may be mere coincidence.