Problems with 3.5
Like in Revised Third Edition, characters roll their ability scores, choose their race, class, starting equipment and other features.
Previously in D&D 3.5, a character obtained new abilities when they reached predetermined levels. A ranger gained an animal companion at level four, rogues gained improved uncanny dodge at level eight, and so on. This caused two problems: First, within certain classes there were places where you increased your level, and gained nothing new besides HP, and base attack/saves. The second was that despite the many many options available to your character through other means, the majority of your abilities were predetermined. One level seven Paladin was much the same as any other level seven paladin.
Another problem with D&D 3.5 was in the races. Each race gave you a set of starting characteristics, so that a level one elven fighter was very different from a level one dwarven fighter. But as levels progressed that initial starting change to characteristics made less and less of a difference, until it was almost negligible.
And while I understand that these, and some other issues present in Revised Third Edition of Dungeons and Dragons have been tackled and changed in Fourth Edition, what they came up with I do not enjoy.
The Ability System
What I have come up with is an Abilities System. What this means is that when a character obtains a new level, they gain a new ability of their choice from sets of lists available to them.
Each class has a list of abilities available to anyone with levels in that class, and a list of prestige abilities which function much like a prestige class within a class. These sets of prestige abilities are called “paths”. For example the barbarian class has a standard set of abilities (Such as Rage, Fast Movement, and Damage Reduction) which are available to anyone with levels in the barbarian class upon attaining a new level. However, a barbarian may choose a certain path of advancement to become a berserker, which allows him to gain abilities exclusive to the berserker path.
Once a character gains a prestige ability from a path, they can no longer gain any prestige abilities from another path. For example if a barbarian takes the berserker path and gains the reckless rage prestige ability, they lose access to all of the prestige abilities from the mage slayer and crazed warrior paths.
Once a character chooses a certain path, they are now referred to by that path instead of by character class. For example: A level 7 barbarian gains enough experience to attain level 8. He chooses to advance to 8th level in the barbarian class, and since he meets the prerequisites he chooses to take reckless rage ability. The barbarian is now a level 8 berserker. The character is still counts as a level 8 barbarian.
Each race now has a list of abilities which are available to members of that race alone, and may be taken upon attaining a new level instead of a class ability.
At first level, and every three levels thereafter (3rd, 6th, 9th, etc…) a character gains a general ability. These general abilities are essentially the same as feats from revised third edition.