Converting RSRD abilities to Echelon talents is usually pretty straightforward.
Many abilities in D&D 3.x are built up of smaller abilities, usually along a path of some sort. Feat paths are pretty obvious (weapon focus and weapon specialization are an example, as is the Mobility feat path leading to Whirlwind Attack, though that’s a short one). Various class abilities improve as a character takes levels in the class (evasion leads to improved evasion, similarly with uncanny dodge, and so on). It isn’t really implemented in D&D 3.x, but it’s not unreasonable to treat access to spells and magic as a path, where knowledge of high-level spells of a particular type implies knowledge of lower-level spells of the same or similar type (if you can cast meteor swarm, it’s reasonable to expect that you can cast fireball… even if D&D 3.x RAW actually doesn’t require or enforce this in any way).
Actions in D&D 3.x got fairly complicated in the end. They range from full-round through standard action, move action, swift action, free action, to immediate action. Plus ‘not an action’, but since those… things people do are by definitions ‘not actions’, I’ll ignore them. There are distinct differences between them, but that’s a lot of different things that can do.
- Standard actions are, for the most part, the ‘standard things characters (and monsters) do’. In many cases this is a single attack, or casting a spell, or something similar.
- Move actions are slightly less good, being anything ‘time consuming’ that isn’t their primary beneficial action. Take something out of a backpack, change position, whatever.
- Swift actions are limited to one per round, but otherwise require a negligible amount of time.
- Free actions are even less than that.
- Immediate actions are much like swift actions but can be done out of turn, almost always as a reaction to an event or another creature’s action (but it uses your swift action from the next round, so it’s not quite free).
- Full-round actions are usually specific things that can be done, often more powerful or beneficial than standard actions. Some spells (but not very many) are full-round actions to cast, and under normal circumstances the only way to get more than one attack in a round is to spend the entire round doing so.
The last point is one of my peeves with D&D 3.x. Unless you have a special ability that gives you additional attacks (such as a flurry of blows, Two-Weapon Fighting, or something similar) or high enough Base Attack Bonus to gain iterative attacks, there is no particular benefit to attacking as a full-round action instead of a standard action. Also, to actually use your improved attack rate you have to spend more precious time on it. In the meantime, your arcane artillery can move just as far (or farther, if augmented) as he could before, and open a bigger can of whoop-ass in the form of more powerful spells. On top of that, the bonus attacks almost always come at a decreasing attack bonus or otherwise suffer penalties.
This is kind of lame.