All users who pre-order the game will receive the M55 Argus assault rifle, a powerful and accurate burst-fire weapon for Commander Shepard.
UK retailer GAME and US chain GameStop are offering the additional N7 Warfare Gear, which includes the N7 Defender armour and N7 Valkyrie rifle. The defender armour increases health, shields, weapon damage and ammo capacity.
Pre-orders through Electronic Arts' own Origin service will receive the AT12 Raider shotgun.
In addition to its story, Mass Effect 3 will feature the co-operative Galaxy at War multiplayer mode.
Galaxy at War will be impacted by the choices made in previous Mass Effect games and will influence the third game's story.
Mass Effect 3 will be available on Xbox 360, PlayStation 3 and PC from March 6 in the US and March 9 in Europe.
> Read our hands-on multiplayer preview of Mass Effect 3
> Mass Effect 3 Collector's Edition adds bonus character, robotic dog