After a seven-year absence (an eternity in videogame terms), Rainbow Six's return is tragically timely, with the recent Paris terrorist attacks causing publisher Ubisoft (which is a French company) to cancel some of the game's planned marketing support. 

Like all its predecessors, Rainbow Six Siege is all about being a key cog in a special forces squad that neutralises terrorist threats. However, the game itself will still be released as planned, and it will be fascinating to find out what the franchise's legion of fiercely loyal fans will make of it.

Unsurprisingly, given how long it has been since the last iteration, Vegas 2, Rainbow Six Siege represents at least a semi-reboot of the franchise. Its core values, fans will be relieved to hear, remain intact: it still disdains respawning and health-regeneration, and all the different soldiers in the game have been drawn from real-life elite forces, including the SAS and FBI SWAT.

But one notable omission will undoubtedly prove controversial: the pre-mission planning phase from previous versions of the game has been unceremoniously dumped. Will that cause die-hard fans to ditch the game, or is this the best Rainbow Six to date?

In some game modes the missions do commence with a period in which everyone pilots wheeled, camera-equipped drones (which, handily, can climb stairs) around the target area, gathering information about the whereabouts of enemies, bombs, hostages and the like. But if you're one of those Rainbow Six fans who derived more pleasure from the planning than the execution of each raid (which, frankly, we could never understand, but we do know such people exist), then your luck is out.

Rainbow Six Siege is also, in the modern idiom, predominantly an online game. But it does have a single-player element, consisting of 10 Situations, in which you solo your way through different scenarios.

These Situations, in effect, are pretty much an extended tutorial, introducing crucial gadgets and techniques as they progress, such as rappelling, leaning around corners and learning how to wield various types of grenades, shields, blast-charges and much more.

Each Situation has three objectives over and above the main one, so there is an element of replayability, along with three difficulty levels, and when you finish the tenth one, you unlock a bonus mission which must be played as part of a five-person co-operative squad.

The Situations also earn you XP – known in Rainbow Six Siege as Renown – and as you level up, you're able to spend that on unlocking Operators. Those are the characters you will play as in the online side of the game, each with a unique loadout (which can be customised to an extent) and special gear.

Pocket-lintsiege2

For example, one Spetsnaz defensive specialist gets a fixed machine-gun which he can pair with a defensive shield. The Operators are drawn from five different special forces groups, each providing two attackers and two defenders.

Rainbow Six Siege encourages you to explore all the different organisations: when you buy, say, your first SAS Operator, the next SAS Operator you buy will cost twice as much Renown.

Once you've unlocked a few Operators, the best way to ease yourself into the game is to take on some of the PvE (Player versus Environment) missions, collectively titled Terrorist Hunt. In those, you always play as an attacker, and part of a five-person squad. You'll either be rescuing a hostage or defusing two bombs, with a defuser which must be carried around (and picked up if the squad member holding it is shot).

Terrorist Hunt is where Rainbow Six Siege's true appeal first manifests itself.

Pocket-lintsiege10

The game's general rigour means that squad members have to co-operate tightly, so almost instantly you find yourself bonding massively with your fellow players – very much in the mould of, say, a team taking on a Raid in Destiny. Happily, it's dead easy to invite your mates to form a squad with you, then take on all-comers. Which should excite the e-sports brigade.

Squad members can revive others who are injured but not instantly killed – restoring half their health – which reinforces the sense of camaraderie.

You swiftly realise the importance of generating a balanced squad – it pays to discuss with fellow players what Operators you should unlock. For example, one of the shield-carrying characters is always handy when advancing into tight spots under fire; but such characters can only shoot a handgun (and will lower the shield when they aim it using the left trigger), so it makes sense for someone else to follow closely with a more powerful and accurate gun.

The full Multiplayer mode is the one which is likely to prove most popular in Rainbow Six Siege, though. Your team will take on another five-man squad of human players over four rounds, with each alternating between attack and defence; if the overall score gets to 2-2, a tiebreak round swings into action.

In Multiplayer, one of the teams will be guarding a hostage, two bombs or a hazardous waste container, and will get some great defensive gadgets, such as metal wall reinforcements, razor-wire, proximity bombs and C4 booby-traps. But the attackers can avail themselves of the likes of EMP grenades, charges that burrow through walls sending grenades into rooms (dangerous when you're trying to rescue a hostage, as killing the hostage will cause the attackers to lose) and flash-bangs.

Pocket-lintsiege5

The result is utterly addictive mayhem, which contrasts massively with a game like Star Wars Battlefront, as it comes with a delicious sense of belonging to a squad with complementary skills.

Like Battlefront, you could argue that Rainbow Six Siege isn't the most substantial game ever –  there are 12 maps, including an Air Force One-style 747 and the SAS's Hereford training centre – but it feels much more of a coherent whole, rather than a randomly assembled bunch of set-pieces.

Siege also feels more run-and-gun than previous Rainbow Six games, which is inevitable given how it emphasises multiplayer action. Whether die-hard Rainbow Six fans see that as a good or bad thing remains to be seen.

Verdict

Old Rainbow Six fans might grumble a bit when they first play Siege due to the lack of a proper planning phase, but it’s such a thoroughly infectious strategy shooter that we’d wager it won’t take long before it wins them over.

The solo play is limited, but it's in multiplayer that Siege really shines. Positioned in among the glut of same-old same-old futuristic shooters this Rainbow Six revamp feels all the more fresh and exciting to play as a result. If, of course, you're into strategy shooters.

Indeed, it might just be the most addictive game we've played all year, having been locked in a room for two days straight with a team of like-minded players, and it still stands out as the most rigorous and realistic first-person shooter you can buy (at least until they get around to making another Operation Flashpoint).