Comparing the 3.5 and 4e Skill Systems

After reading through the 4th edition Player's Handbook, it struck me that the Dungeons & Dragons 4e skill system has two main mechanical changes from 3.5:

  1. Rather than continually paying points into specific skills, characters receive a bonus equal to one half their level on all skills.
  2. The difference between being Trained (i.e. having a class skill) and being untrained (having a cross-class skill) is a flat +5 bonus, rather than a cost difference and skill point cap.

Hypothesis: this makes it seem like the gap between skilled and unskilled characters would be much smaller in 4th edition than in 3e.

To verify my hunch, I mapped out what skill modifier characters would have under 3.5 and 4e if they were a) horribly bad at a skill and b) very good at it. I assumed that under both systems characters who are bad at a skill have a -2 ability modifier in the relevant statistic and never use skill points, take training, or buy feats to help with that skill. I assumed characters who are good at a skill begin with a relevant ability modifier of +5 and take Training or increase the skill at every level, if possible. I also granted racial and feat bonuses to the skill.

In other words, I use this math:

3.5 Bad Skill:-2 from Ability Score modifier, no other modifiers (you never buy items or try to get better at this skill).
3.5 Good Skill:(level +3) ranks + 5 for Ability Score modifier + (level/8) from improving the relevant Ability Score as a character gains levels + 2 racial bonus + 3 feat bonus
4e Bad Skill:(1/2 * level) - 2 from Ability Score modifier
4e Good Skill:(1/2 * level) + 5 for ability score modifier + (level/8) from improving the relevant Ability Score as a character gains levels + 2 racial bonus + 3 feat bonus + 5 for Training.

Plugging these formulas into a spreadsheet, we get the following table.


3.5 Bad Skill 3.5 Good Skill 4e Bad Skill 4e Good Skill
1 -2 14 -2 15
2 -2 15 -1 16
3 -2 16 -1 16
4 -2 17 0 17
5 -2 18 0 17
6 -2 19 1 18
7 -2 20 1 18
8 -2 22 2 20
9 -2 23 2 20
10 -2 24 3 21
11 -2 25 3 21
12 -2 26 4 22
13 -2 27 4 22
14 -2 28 5 23
15 -2 29 5 23
16 -2 31 6 25
17 -2 32 6 25
18 -2 33 7 26
19 -2 34 7 26
20 -2 35 8 27

This can be seen nicely as a graph.

The hypothesis seems to hold: while the gap between characters in 3.5 increases dramatically, it stays roughly the same at all levels in 4th edition.

I suppose this makes sense if the intent of 4e is to make playing D&D more appealing to the casual gamer. The 3.5 system favours the specialist - characters who concentrate on doing one or two things well are rewarded by being able to beat skill DCs much more easily. The 3.5 system also lends itself to micromanagement of skills, where players can choose exactly how to spend their skill points at each level. While arguably useful, it does take more effort and knowledge. The 4e system, meanwhile, favours simplicity - all skills increase as characters advance in level without having to worry about where to spend a character's points, and the difference between being trained and untrained is not as drastic, meaning players don't have to spend as much time or energy worrying which skills to choose.

Does this mean anything else? I'm not sure. But it's interesting to note.

TODO: more research


Further Questions:

  • Do differences in DC progression or magic item availability between 3.5 and 4e change this graph?
changed January 5, 2009