None of what you're describing sounds familiar to me. Are you reading some sort of promotional material, or something? Insight and Perception are both skills (and both are based on your Wisdom ability). Your bonus to Insight/Perception skill checks (roll d20 and add your modifier) is your (Wisdom modifier) + (1/2 of your level round down) + (5 if you have the skill trained). Some characters may also get additional bonuses from features, powers, feats, or items. Insight and Perception are also special in that they have "passive" values, which are equivalent to rolling a 10 on the d20 (so, 10+WIS+1/2Lvl+Trained). Your Fortitude defense is 10 + (1/2 your level round down) + (greater of STR or CON modifiers). There are classes, feats, and items which can increase this as well. All magical Neck slot items (cloaks, amulets, etc.) grant a bonus to Fortitude, Reflex, and Will defenses. Reflex and Will defenses behave in the same way, using the other four abilities. You seem to understand how ability modifiers are derived, although I usually see it as (Ability - 10) / 2 rather than (Ability / 2) - 5. 8-9 is a -1 modifier, 10-11 is 0, 12-13 is 1, 14-15 is 2, 16-17 is 3, 18-19 is 4, and 20 is 5. You can't go above 20 at character creation (18 plus a racial bonus), although you can get a total of +8 more from levels 4 through 28 (for a modifier increase of 4). A Rogue's HP at level 1 is 12+(Constitution). That's your full Constitution ability, not the CON modifier. Each level after that, you gain 5 HP. So, if you had 10 Constitution, your level 1 HP would be 22; since your healing surge value is 1/4 of your maximum HP, your surge value would be 5. A Rogue also has 6+CON modifier healing surges he can use each day, so that Constitution-10 Rogue would have 6 surges. Once per encounter, while you are bloodied (at or below 1/2 HP), you can use a Standard action to take a Second Wind: you spend a healing surge and get +2 to all of your defenses for a turn. During a short rest (a few minutes of in-game time between encounters), you can spend healing surges as much as you please to heal up. Outside of short rests and Second Wind, you can't spend healing surges without a power or item instructing you to do so. (You heal to full and regain all of your surges after an extended rest.)