Celtic Heroes

The only way to "go past 50" is with direct skill boost items. Sure you will still have 50 points in the skill, but there are items that provide a direct boost to skill damage or heals. For example, Mordris bracelets or Samhain 2014 rings do this. Once you hit 50 skill points, that is the only way you can boost your skills significantly.

Or just stat points.

Stat points too, although at a certain point adding stat points produces diminishing returns. However, more stat points are always useful

Stat points too, although at a certain point adding stat points produces diminishing returns. However, more stat points are always useful

Ability points do the same thing. However it's not a ton - but it does apply to all skills that rely on it whereas direct add points apply just to the skill just like stat points.