Positioning for Kassadin by class, range and real stat line — what to do when the fight starts, and what not to.
Kassadin is a assassin. In a five-on-five that means one thing: delete one target and leave, which makes target selection matter more than the fight.
Items, runes and damage numbers are all downstream of standing in the right place when it starts.

| Stat | Level 1 | Level 18 |
|---|---|---|
| Health | 646 | 2567 |
| Attack damage | 59 | 59 |
| Armour | 21 | 89 |
| Magic resist | 30 | 52.1 |
Movement speed 335 and attack range 150 do not grow with levels — they are the two numbers that stay true all game.
At 150 range you are inside the fight by definition. The question is which side of it — entering on the same angle as your team makes you a threat, entering alone makes you a kill.
The armour and magic resist above are what you have before items, and they are the honest answer to whether you survive being focused.
Kassadin takes reduced magic damage and ignores unit collision.
Kassadin fires an orb of void energy at a target, dealing damage and interrupting channels. The excess energy forms around himself, granting a temporary shield that absorbs magic damage.
Passive: Kassadin's basic attacks deal bonus magic damage. Active: Kassadin's next basic attack deals significant bonus magic damage and restores Mana.
Kassadin draws energy from spells cast in his vicinity. Upon charging up, Kassadin can use Force Pulse to damage and slow enemies in a cone in front of him.
Kassadin teleports to a nearby location dealing damage to nearby enemy units. Multiple Riftwalks in a short period of time cost additional Mana but also deal additional damage.
These are the designers' words, not ours — the tips shipped in the client for Kassadin.