XCOM: Enemy Unknown class guide: how to use the Assault, Support, Heavy and Sniper

Often, levelling up a videogame character feels less like moulding a living being to your unholy will as pouring slow-working acid over the enemy line-up. 20 hours have passed and your Arch-Mage Conquistador now chops off a tidy 999 HP a hit, but how exactly said Conquistador wages war hasn't really changed, and as a consequence, the customisation element seems rather pointless.

Friend, you need to play some XCOM: Enemy Unknown. A maxed-out XCOM character isn't window dressing - he or she's a carefully nurtured and tailored entity, astonishingly powerful but only in the right circumstances. Send that trooper into the wrong circumstances, and all the hitpoints in the world won't save the unfortunate soul from being routed and slain like a yearling calf. With a view to avoiding all that, here's a guide to XCOM's initial four classes. You can also unlock a Psionic class and mobile weapons platforms (remote-controlled tanks) through research, but I'll let you discover those on your own.

Overview

Each class has around a dozen abilities to unlock, generally a couple per military rank, but you won't be able to unlock everything for one soldier. Ten abilities are grouped into pairs, and you can only unlock one ability per pair. Classes thus branch naturally into two specialised subtypes, depending on whether you pick the left column or the right: a Sniper, for instance, can be a super long-ranged dude who doesn't move around much, or more of a mid-range supporter, rubbing elbows with your Heavies. It's also possible to mix and match abilities from both columns, of course, creating subtypes of your own.

Every rank a soldier gains adds to his or her health, accuracy and Will stat, which governs how likely the soldier is to panic in battle. One thing to remember about Will is that it's permanently lowered when a soldier suffers a critical injury (i.e. has to be revived). In practice, this doesn't seem to happen often enough on Classic and Normal difficulty to pose problems, but if your veterans have more scars than fingers, keep an eye on them. The last thing a squad needs is a tooled-up Heavy losing his rag and hosing everybody with plasma.