If you buy a class skill, your character gets 1 skill rank (equal to a +1 bonus on checks with that skill) for each skill point. If you buy other classesâ€™ skills (cross-class skills), you get 1 rank per 2 skill points.
- Your maximum rank in a class skill is your character level + 3.
- Your maximum rank in a cross-class skill is one-half of this number (round down).
Using Skills: To make a skill check: 1d20 + skill modifier (Skill modifier = skill rank +ability modifier + miscellaneous modifiers). This roll works just like an Attack roll or a Saving throw â€” the higher the roll, the better. Either youâ€™re trying to match or exceed a certain Difficulty Class (DC), or youâ€™re trying to beat another characterâ€™s check result.
Skill Ranks: A characterâ€™s number of ranks in a skill is based on how many skill points a character has invested in a skill. Many skills can be used even if the character has no ranks in them; doing this is called making an untrained skill check.
Ability Modifier: The ability modifier used in a skill check is the modifier for the skillâ€™s key ability (the ability associated with the skillâ€™s use EG. Str, Dex and others). The key ability of each skill is noted in its description.