I felt like it was a good idea to make a meltdown guide that would be helpful for players of all skill and familiarity levels. I see a LOT of people playing this mode really incorrectly, and yes, there is always a more correct way than another. some ways may work some of the time, but that does not mean that they are the wisest ways.
at the beginning of the game, forget about killing players. at best, just keep them back. if even this becomes an issue where you are taking damage from your actual health pool, you are probably already too far up and need to think about retreating. the goal for the first many waves is to just kill your minions and, if possible, keep them from killing your minions as well. there is absolutely no reason for you to be going for player kills at level 1. bide your time and wait until you are stronger than your opponent. the goal in early meltdown is to never actually try to kill another player unless one of two conditions is present: they are out of position and overexteneded, or you are already significantly stronger than them. you get stronger than them by being smarter than them, not by trying to kill them initially. the more damage you take, the more you have to go back to base or go heal up at the healing station.
shards, gear, level, and buildables to support middle control is all that is important before you hit 250. you should take out their accelerators asap, but this is mainly for xp, and secondarily for the guy that overextends so he cant run away. it is NOT for you to be able to chase them into their turrets, spawn, or healing station at the beginning half of the game. if you have a marquis or some other ranged character that can snipe out their turret early on, then great, but that is more of another way of getting xp and being able to barely cross into their side of the map to kill the guy running away that overextended.
do NOT try to spawn trap minions at their accelerator whether it is down or not. it makes NO sense. you do not have an overshield from your shepherd, so you will take damage. the goal is to NEVER take damage while clearing minions. if you have middle control pre 250, that is all that matters. no need to stand at the accelerator taking damage from minions and ranged opponents. start getting some elite minions in to get to 250 incredibly fast.
once you start nearing 250, if you have done everythign i said prior to this, you will be outleveling your enemy, your gear will be ready, and you will be in a perfect position to then push up and take out their turrets, supply, etc., and just spawn trap them the rest of the game.
you need to have a rough idea of who will be in what lane at the beginning of the game, but you also need to be able to change depending upon where the enemy puts their 5th player, and the composition of both lanes. but the ideal situation is that you do not have to switch lanes at any point in the game, pre 250. you should have strong enough compostion to be able to support a lane independent of calling out for help from the other lane. you are robbing peter to pay paul if you do so.
So last night i was playing with one other friend. We got stuck in a game of meltdown that really neither of us has the desire to play anymore. We ran into a team of 2 and a team of 3, while we were the only group on our team. They were all level 100, all wearing master skins, etc. They had a miko, reyna, boldur, montana, caldarius. i was playing phoebe, while my friend was playing melka. the other team did as they should and put one tank in each lane, with one nut-hugging support on each. we really had nowhere near enough burst early on in this game to deal with a tank/support combo in a 2v2 situation in a lane. we couldnt even get in to clear the minions. so i told my friend that i wanted to try out this strat that i was talking about below in regards to lane stacking when you are terribly outmatched composition wise.
so we decided to abandon our lane entirely. we put all 5 players in one lane, leaving the miko/boldur/rotating caldarius that was on our lane. we flooded the other lane and wiped their reyna montana that the other lane was also having trouble doing anything about. it was 5v2, of course we wiped them. we cleared that lane, they resapwned, and it wasnt long before they pretty much all came back to the lane we had rotated to. at that point, me and my friend left that lane entirely, cleared the other lane of minions, then as they rotated over, the first two got killed before the slow tanks could get over and we just rotated back when they did.
this lane stacking is very effective against non 5 man premade teams. it would even confuse 5 mans, but ultimately would probably not work out that well long term. but it definitely served its purpose and the other team, with way better composition, rage quit within 10 minutes of the game