Borderlands is an excellent FPS and RPG hybrid. For more information, read my Borderlands review. There are four characters to choose from and each one has a specific set of skills which can be developed in their skill tree. Like any typical RPG you can level up periodically by building up experience and earning skill points. Those skill points can unlock new abilities but the maximum cap is 50. This means no player can go above level 50 (you only get 45 to spend in the original game and 47 with the add on pack). It also limits your possible choices within the skills tree so you have to specialize and choose the skills you find more appealing.
Any character can wield any weapon, although specific weapons will probably suit your character better than others. You can check out our Borderlands Weapon Guide for more on the vast array of guns in the game. Here we are going to focus on two builds for the Soldier, offensive and defensive. The Soldier is a good support character with potential medic abilities and some devastating offensive skills.