Physical damage is one of the three types of damage in League of Legends, the others being true damage and magic damage. Physical damage is dealt by all autoattacks, by some champion abilities and by some item effects.
Statistics influencing physical damage
Most physical damage is based on the champion's attack damage (but not all damage based on attack damage does physical damage). The physical autoattack damage is increased by attack speed, critical strike and armor penetration or reduction. A small number of champion abilities that deal physical damage can be strengthened with ability power.
Not all physical damage sources proc life steal, but most that apply on-hit effects do.
Champion abilities dealing physical that don't proc on-hit effects usually proc spell vamp.
The amount of physical damage received is reduced by a certain percentage based on the target's armor or other damage reducing effects, such as 
Unbreakable Will de 
Alistar. The effectiveness of armor can be reduced with armor penetration or reduction.
Items that deal physical damage
Blade of the Ruined King: Unique Passive: Your attacks deal 5% of the target's current health in bonus physical damage (60 max vs minions). Unique Active: Drains target champion, dealing 15% of maximum health as physical damage (minimum 100 damage) and healing you by the same amount. Additionally you steal 30% of their movement speed for 2 seconds - 90 second cooldown. +25 attack damage, +40% attack speed, +15% life steal 3200 de oro..
Iceborn Gauntlet: Unique Passive - Icy/Spellblade: After using an ability, your next basic attack deals bonus physical damage equal to 125% of your base attack damage to surrounding enemies and creates a field for 2 seconds that slows enemies inside by 30% (2 second cooldown). +40 ability power, +500 mana, +60 armor, +15% cooldown reduction. 3250 de oro..- Muramana: Unique Active Toggle: Dealing damage with single target, non-periodic spells or your basic attacks will consume 3% of your current mana to deal 6% of your current mana as physical damage. Unique Passive - Awe: Gain attack damage equal to 2% of your maximum mana. +1000 mana, +20 attack damage, +7 mana regen per 5 seconds. 2100 de oro. (Cannot be bought, obtained by transforming from Manamune)
- Ravenous Hydra: Unique Passive – Cleave (Melee only): Your attacks deal physical damage up to 60% of your Attack Damage to units around your target, decaying down to 20% near the edge. Unique Active – Crescent (Melee only): Deals physical damage up to 100% of your Attack Damage to units around you, decaying down to 60% near the edge. (10 second cooldown) +75 attack damage, +15 health regeneration, +12% life steal. 3300 de oro..
- Runaan's Hurricane: Unique Passive (Ranged only): Your basic attacks fire minor bolts at 2 nearby targets, each dealing 10 + 50% of your attack damage and applying on-hit effects. +70% attack speed. 2750 de oro..
- Sheen: Unique Passive - Spellblade: On cast, your next autoattack deals additional physical damage equal to 100% of your base attack damage. 2 second cooldown. +25 ability power, +200 mana. 1200 de oro..
- Tiamat: Unique Passive – Cleave (Melee only): Your attacks deal physical damage up to 60% of your Attack Damage to units around your target, decaying down to 20% near the edge. Unique Active – Crescent (Melee only): Deals physical damage up to 100% of your Attack Damage to units around you, decaying down to 60% near the edge. (10 second cooldown) +40 attack damage, +15 health regeneration. 1900 de oro..
- Trinity Force: Unique Passive - Spellblade: On cast, your next autoattack deals additional physical damage equal to 200% of your base attack damage. 2 second cooldown. Unique Passive - Rage: Your basic attacks grant 20 movement speed on hit for 2 seconds. Minion, monster and champion kills grant 60 movement speed. +30 ability power, +30 attack damage, +30% attack speed, +10% critical strike chance, +250 health, +200 mana, +8% movement speed. 3628 de oro..
