Starcraft 2: Marine Arena Strategy

Been a while since I wrote a strategy update for Starcraft 2, but here is one for my favorite custom map, Marine Arena. The basics of this map is just spawn marines and mercenaries (which are different units who have different abilities), and kill the opponents base. This is difficult because you need minerals to buy mercenaries and heroes and to upgrade your units. You get fixed amount of minerals automatically every 10 minutes and a variable amount of minerals depending on how many enemies you kill.
Most Marine Arena games are on Classic setting, with either classic or fast mode. This guide is for Marine Arena 1.1 the latest version.

Edit: Made a video to show the basics of the custom map.

Opening:
I usually open with either Zealots or Zerglings because either of those units are good at killing marines, and they can be upgraded with charge / speed in a fast game immediately. With those upgrades and your marines, you have a pretty good starting army to make kills. Usually you keep doing this until you have enough minerals to upgrade your marines / mercs setting the way for the mid game.

Mid-game:
When you have enough minerals, usually after your first 10 minute income comes in, you have two choices: tech marine, or tech merc (I hate heroes so I don’t go suggest that route). I recommend tech merc because marines take a while to upgrade and are not that worth it early on. When you tech merc there are several options:
-Zergling to Crackling. Upgraded cracklings can be hard to beat, since they can attack so fast. With full attack speed upgrades they can reach 0.29 attack speed probably the highest of any unit. Combine this with decent weapon / armor upgrades and cracklings can be deadly. I would choose this route if you started with Zerglings.
-Zealot to Warpalot. Warp Zealots are efficient beaters against biological, the most common type of unit in Marine Arena. However, Warpalots don’t need many upgrades, so this route saves you some minerals to tech marine later on. I would choose this route if you started with Zealots and your opponents have a lot of biological.
–Beetles. I don’t usually choose Beetles but you can do it if you micro well. With a lot of armor and burrowing skills, Beetles can be deadly. They have the highest bio damage in the game.
–Immortals can be a good unit choice against armored or mechanical. They do massive damage and have a special ability that limits how much damage they take.
-Firebats / Devil Dogs. Great for taking care of bio units. Devil dogs are armor heavy so you can upgrade the armor and they’ll be very hard to take down. Cannot attack air however.
–Goliath. I recommend this route if you see other players having air units. Otherwise they’re not that great.
–Maraiders. The upgraded version of Marauders, Maraiders are nice for being able to hit bio units air and ground, however for ground, they are not as efficient as warp zealot or devil dog. I recommend saving up for Stalker lancers instead as their armor makes them harder to kill.
–Reaver. GREAT choice if you don’t see other players having air units. Reavers cannot attack air, but they are great against any other ground unit, be it marine, firebat, zealot, etc. Upgrade their armor is crucial because armored Reavers become great tanks.
–Stalker Lancers. A good armored unit that can hit ground and air and good against bio units. If you upgrade the armor enough they become very difficult to kill. Their protoss shields get double the armor of other units. I usually get armor first followed by protoss shield and weapon and health. A good all around choice if you can’t decide between Goliath or Reaver.
–Hybrid Destroyer. Good for killing air and ground units, and against mechanical.
–Hydralisk / Brutalisk. Not as armored as Stalker Lancers, but more health. Hydralisks are very powerful with upgrades. I don’t suggest upgrading to Brutalisks because while they have a lot of health, they spawn and attack too slowly. They both have ability to produce broodlings which inherit the hydra / brutalisk stats, which can be very powerful. They can both hit air however, so your choice between Stalker lancer and Hydra / Brutalisks is just a matter of Armor vs. Health.

Late-game:
Late game there really only is one choice: Tech marine. once you upgraded your mercs to a decent level (that depends on choice of merc), tech your marines. Marines need ALOT of minerals to upgrade fully, thats why they are late game material. However, they are still the strongest units when fully upgraded because of their numbers. They are the only unit you can increase the spawn rate for. Weapon and Range upgrades are the most crucial. I usually get about 6 Atk and max out my Range at 6 (at the marine shop) before I increase the spawn rate. I also get a bit of health on them before I get Stim-pak. Weapon speed is also an important upgrade at the marine shop, but not as important as Range. If you have high damage but no range, there’s no point because your marines will get outranged and die. Since marines are the end-game, you keep upgrading them for the rest of the game because they can pretty much stop any mercenary when you have enough of them.

Heroes
–Dark Templar is a popular choice because of their cloaking and how fast they move. However they require good micro and if the opponent has a support tower they can scan almost all the time.
–Infestor is nice for the fungal growth, but like the dark templar needs to be hidden and requires good micro.
-I’ve also seen players make good use of the Raven for its special abilities and turrets.
–Colossus are nice for taking care of small bio units like marine and marauders. Its range is the primary advantage. If upgraded to Chibi-colo, they possess an extremely fast attack speed of 0.7 and can be recalled, making them quite devastating. They are good anti-hero units with its Ragnarok beam.
– Thor is nice for anti-air, when you need some extra support for taking care of annoying mutalisks or wraiths.
–High templar is always nice for psi-storming, and if upgraded enough, can be unstoppable with recall, but require good micro.
–Archons are extremely powerful but needs lots of dedication to a hero build, due to the level you need for dark templar and high templar.

Table for Mercs/Heroes

My personal suggestions: Stalker lancer, Reavers, Devil dogs or Warp zealots for countering bio, Crackling or Hydralisk for countering armored, and Goliath for countering air. and High templar / Colossus for general protection against marines / light units. If your teammate is someone you know well, good merc combinations involve Destroyer/Reaver, Stalker lancer / Hydralisk, Goliath / Reaver, Devil Dog / Crackling, etc anything that can take care of both bio and armored units, and can tech to anti-air easily.

Other tips
-Build a support tower sooner or later. Sooner if they have DT or infester or ghost, later if they don’t.
-Kill the rubble on the platform beside you as soon as you start, else it will cause trouble later on.
-Try to secure the towers on the platforms beside you as they give you range.
-Your partner is important, make sure he knows how to play, or if he quits after the game starts, take control of his guys and use them.
-Mass recall is really good. Get a support tower and you can use it to recall your heroes when they are almost dead (when your colossus or HT runs out of shields). And then heal them to full once they get back.
-Mercenary/Marine shop at the center of the map is important for upgrades. Important Marine and Merc upgrades are there. Guarding the shops can be a good strategy against opponents.
-Burrow a zergling at each corner to get good observation of each team.
-Burrowing Beetles / Cracklings / Tanklings are good for surprise hits.
-Reason I don’t mention Tanklings is because Cracklings can become Tanklings by upgrading health + atk.
-Marauders are okay, and Maraiders are okay too, but not as good as other mercs.
-I don’t suggest air units unless you know all other players have ground units that can’t attack air. If you do, Mutas or Void rays are good for harrassing. Wraiths are good for anti-air.
-When you have air or highly teched marines, you can kill his mercenary compounds really easily and force them to rebuild. If you have a support tower, you can scan and drop in Merc Marines as an easy way to kill his compound. Only if your Marines are highly upgraded.
-Some people buy battlecruisers early in the game to gain an advantage. This could work because the early lead is the most important.
-An early savior in the game can also put you ahead of your opponents and keep you there, only if you get alot of kills off of it though.
-Also if your marines are highly upgraded and so are your opponents, you can probably kill his command center more easily than you can kill his guys.
-Share control with your partner if you know him well.
-Another strategy is when your opponent rushes you early and has a lot of guys, you can savior early to put you in the lead. This works well in classic games where early minerals are crucial, and an early lead can often mean keeping that lead and winning the game.
-When you see air units, tech to Goliath or get a Thor.
-You can rush your opponent early by having you and your opponent both get zerglings / meta boost or zealots/charge before the vote even finishes and attacking his base.
-Kill early, kill often, and remember strength comes in numbers. Thats the way to getting lots of kills, and the person with the most kills usually wins the game.
-Good merc combinations involve Crackling, Devil Dog, Reaver and Goliath as I feel these to be the best mercs all around.
-Medivacs can be useful if you are using bio units like marines, maraiders or devil dogs heavily.

Example strategy:
-500 starting minerals in a fast game.
-Build Zergling and research metabolic boost, or Zealot. (250 minerals total).
-Kill some guys until you have 750 minerals total. Remember you still have 250 minerals leftover from before so you need to get 500 minerals before the first income hits.
-Upgrade to Cracklings and research adrenal glands, or upgrade to Warp Zealot. (750 minerals total).
-Ideally, the first income should hit about now at 10 minutes.
-Get a radio tower. (100 minerals).
-Kill some guys until you get enough to upgrade to 2 armor and 2 weapon on your Cracklings/Zealots. (1075 minerals total).
-Start upgrading your marines. Kill guys and wait for income. You should have at least 2 range upgrades and 4 weapon upgrades before you increase their spawn rate. (1650 minerals total).
-If you see your Zealots/Cracklings getting killed by air, switch to Goliaths, or if they are getting killed by bio killers like Devil Dogs / Warpalots, switch to Reavers, Beetles or Devil Dogs. Stalker Lancers and Brutalisks are also good choices for having a unit that can hit air/ground equally well. Remember to upgrade them at the merc shop. This isn’t that necessary if your partner has something that counters them already.
-Get your marines up to at least 3 range upgrades and 6 weapon upgrades before you do anything else. (2775 minerals).
-Get a support tower. (300 minerals).
-After that, upgrade your marines / mercs as you see fit at your command center or marine/merc shop.