Can’t go to the beach because it’s covered in Chryssalids? Tired of 98 pound Sectoids kicking plasma in your face? Worry not, friend. Colonel Atlas has a plan for you.

The learning curve on Firaxis’ XCOM: Enemy Unknown ($9.99) isn’t as steep as on Julian Gollup’s original, but there’s a lot of depth to this game, and the interplay between the game’s tactical combat and resource management layers is crucial to success. Like the original X-Com / UFO: Enemy Unknown, you can lose this game by inches, working yourself into an unmanageable position with terror levels rising across the world.

Even if you win all of your battles, you can still lose the war by failing to make progress toward assimilating alien technology and understanding their goals.

Combat 101

• Tanks, but no Tanks – XCOM is a turn-based cover shooter. Armor helps your units survive one, maybe two hits, that’s it. An exposed squaddie is a dead squaddie. Even the heaviest of your SHIV support vehicles can easily get toasted in a single round.

• The Best Defense is a Cautious Offense – at the same time, rushing headlong toward the enemy, even to claim a kill before they get to act, invites tragedy. Advance slowly, from cover to cover, and plan on leaving a few of your units with good line of sight free for overwatch (response) attacks.

• Work the Numbers – pay attention to your to-hit chances. Cover works both ways, so if you’ve got a low-probability shot, you’re often better off taking overwatch and hoping your enemy steps into view. Also remember that a height advantage makes it easier to land hits and harder to get hit, and that units in smoke are harder to hit, but suffer no penalty to their own attacks (unless the enemy is also in the smoke cloud, a tactic the AI favors).

Base Basics

• Excavate Early and Often – dig out empty space before you need it, as building new facilities takes a long time, and you don’t want to have to wait extra days to clear the room you need for that new thermal power plant or psionic training facility.

• Eye in the Sky, Money in the Bank – it takes about 20 days to build a Satellite Uplink facility, and just as long to build the satellites themselves, which the game won’t let you do until you have uplink capacity for them, so plan ahead and make this a top priority at the beginning of a new game. Also, make sure you order at least one interceptor (from the Hanger) for each continent you’re launching satellites over, so you can protect them.

• Engineers Rule, Scientists Drool – you need more engineers than scientists. At least twice as many engineers and workshops. Between Foundry Upgrades and building gear, you’ll use them more, and the cost per item, in terms of alloys and Elerium as well as credits, is based on how many engineers and workshops you have. As if that wasn’t enough, certain items and upgrades require a minimum number of engineers.

• Training Day, Officer Hoyt – as soon as you can (right after the first mission on Normal difficulty) buy the Wet Work ability in Officer Training. +25% XP gain is something you can’t live without. Upgrade your squad size immediately when you unlock those training options. There’s one other bit of training you need as soon as you can get it: the automatic Rookie level-up to Squaddie, so when you get new troops, you immediately know what they’re good for, instead of having to take them into combat with no skills once or twice just to find out their character class.

Human Resources

• Support – don’t underestimate the Support squaddie. If I had to pick just one class to play the entire game with, it’d be Support. If you have a dedicated medic, you’ll want a Support unit for that job, but that’s not all. Support units with more combat oriented skills are the best scouts and medium-range fighters in the game, with high versatility and my single favorite ability: high-level Support squaddies get an extra accessory slot, and a properly kitted-out Support unit can fill any role. Treasure a Support unit with Psionic talent: that piece of the puzzle makes a medic into a one-soldier hospital and headshrinker, and turns a combat Support squaddie into (IMHO) the deadliest unit in the game.

• Sniper – there are a couple of classes that you can nerf if you take the wrong ability early on: for my money, a Sniper’s not a sniper until (and unless) they get Squad Sight, allowing them to target enemies in any of your units’ spotting radius as long as they have line of sight. If you then take the Gunslinger ability at your next level up, you can then use your sidearm to devastating effect after moving, negating the value of the Snap Short ability  A well-placed Sniper is your long-range, fire support, and defensive umbrella (on overwatch) all in one. The weaknesses of this class are that you will more-or-less always want to equip them with a Scope, foreclosing any other use of their Accessory slot, and that the best sniper rifle can only be built (at great cost) not captured from the enemy.

• Heavy – the second time the Heavy levels up, the Bullet Swarm ability can be chosen. Forget Holo-Targeting, take Bullet Swarm. The game’s description makes it sound like this ability allows you to move after firing, but it’s much more useful than that: as long as your first action is a basic attack, you can do anything with your second “move" including making two attacks in the same turn, attacking and going on overwatch, or even firing your gun and then launching a rocket. This makes your Heavy soldiers into the rooks of XCOM: place them well at the end of your turn, and they can unleash hell the following round.

• Assault – these are your close-in fighters, or depending on the abilities you select and their equipment loadout, strong mid-range riflemen. The game says that “most" of your squaddies will be Assault-class, but that’s a scurrilous lie. About 25% of your new recruits will be Assault-class, the same as any other type. That matters, as your Assault units are more likely to get killed than any other type, especially until you get some decent armor. If you’re optimizing an Assault squaddie for close combat (close = shotgun), focus on defensive abilities – they’ll need them. The mid-range variant can focus more on damage boosting abilities.

Intermediate Tactics

• Set to Stun – alien weapons have a deadman switch: kill that Sectoid, and his gun bursts into fragments. If you stun him, however, that plasma weapon is now yours. This is by far the easiest way to outfit an entire team with plasma guns, but your Arc Projector caps out at a 70% chance to hit. The advanced Arc Projector project boosts that chance all the way up to a maximum of 95%, making it the most essential upgrade in the Foundry.

• Blast ’em – the Blaster launcher shoots a smart bomb that can literally turn corners to hit its target, but this powerful replacement for the Rocket Launcher is a hidden piece of tech. You have to research enemy fusion cores to get it, and those are only found on their battleships. If you’re doing well, you might not be seeing battleships: to lure one out, ignore a regular contact with a UFO and wait. There’s a good chance a battleship will show up next to take advantage of your lassitude. Now all you have to do is shoot it out of the sky and take out its entire crew. Cakewalk.

• Out of the Frying Pan – Suppressing fire (Heavy, Support, SHIV) is a good way to reduce the threat value of an enemy you can’t take out this turn, but it has more uses than that. You can use it as a more focused alternative to overwatch, and to negate an enemy’s reaction fire (especially valuable against Muton Elites and Sectopods). But there’s one more combo that’s less obvious: Suppression allows you to take a reaction shot on your turn. When an enemy has good cover, you can use the Assault unit’s Flush ability to inflict a little pain and force them to move. The problem is that flushed enemies tend to move to another hiding spot. However, if you have one or more units suppressing the enemy before you Flush them, they will all take their shots as soon as the target is exposed. Squish.

• Hushabye Muton – the Ghost Armor may seem underpowered, as you can only go invisible four times per mission, the effects only last one turn, and are lost if you open fire. If going invisible took an action, the suit would be nearly useless, but “stealthing" is the only free action in the game. The enemy completely ignores invisible units, offering unprecedented new strategies (my measure for great ability and gear). Ghost Armor is great for scouts (usually Support or Assault units), and can provide your Sniper with a little extra security, but it’s best used to set up flanking attacks and ambushes. It may sound paradoxical, but Ghost Armor was made for the Heavy squaddie. Go invisible, waltz right past enemy lines, and then open fire the next turn. If you position yourself well, you’ll be able to make two flanking attacks (with Bullet Storm) and they’ll never know what hit them.

In the end, a large part of the fun of XCOM is coming up with your own squads and strategies. These tips should help you get going and avoid missing key advantages. Advanced strategy is all up to you: you may find a way to make Holo-Targeting pay off, or a mind-blowing combination involving smoke grenades and Archangel armor. You can share your favorite strategies and tactics in the forum or in the comments below.