Minions are units that comprise the main force sent by the Nexus. They spawn periodically from their nexus and advance along a lane towards the enemy nexus, automatically engaging any enemy unit or structure they encounter. They are controlled by artificial intelligence, and only use basic attacks.
These graphics show the points at which minions spawn in Summoner's Rift and Howling Abyss, and the routes they follow after they spawn. The spawning points are the thick and short segments at the ends of each red/blue line. Immediately after spawning minions march along the routes marked by the thin parts of those lines:
The very first minion wave is ghosted for a few seconds:
Top and bot lane minions are ghosted for 28 seconds.
Middle lane minions are ghosted for 18 seconds.
Minions walk along a lane until they find an enemy unit. When they find an enemy unit, they attack it. Champions aggro enemy minions when they attack a nearby enemy champion with basic attacks, targeted abilities or spells. When minions find several enemy units they choose their target using a priority system that follows this order:
Enemy champions attacking an allied champion.
Enemy minions attacking an allied champion.
Enemy minions attacking an allied minion.
Enemy turrets attacking an allied minion.
Enemy champions attacking an allied minion.
The closest enemy minion.
The closest enemy champion.
Once a minion has chosen a target, it only switches to a new target if the new target has higher priority. If they see a new target with the same priority as their current target, they keep attacking their current target.
Minions reevaluate their target every few seconds. For instance, if an enemy champion attacks an allied champion and then stops attacking, minions will keep targeting the enemy champion for a short time after he stops attacking.
When the target of a minion leaves its sight, the minion switches to a new target or keeps advancing if there are no targets left within sight.
Every 90 seconds (i. e., every third wave) minions upgrade, increasing their strength.
Minions deal 50% reduced damage to enemy champions.
The armor of turrets is reduced when enemy minions are nearby.
Minions start with 325 movement speed and gain 25 / 50 / 75 / 100 (based on minutes) movement speed as the game progresses.
New spawning minions level up based on their team's average level (e.g. one level 15, 10 and 18 would make a minion level 14).
Some items affect the way champions interact with minions.
The following items affect the amount of gold received from minion kills:
Destroying an enemy Inhibitor provides a small buff to allied minions in the lane where the inhibitor was destroyed.
Minions in the team with higher average champion level receive a buff that increases the damage they deal and reduce the damage they take, which is proportional to their lane's turret advantage and their team's level advantage.
Creep Score (CS) is the number of minions, monsters, and champion pets a champion has slain by dealing the killing blow to these units. Dealing this hit is known as last hitting and is considered one of the most important skills in League of Legends.
In the early and mid game, CS along with KDA can be used to compare how well a player is doing against their lane opponent.
As of V8.23, a minion wave has an average gold value that varies from 125 and up to 195 at 25:00.
Average gold per wave
(3 × 21) + (3 × 14) + (60 ÷ 3)
(3 × 21) + (3 × 14) + (84 ÷ 2)
(3 × 21) + (3 × 14) + (90 ÷ 2)
(3 × 21) + (3 × 14) + (90)
Without player interference a lane's wave is neither advancing or retreating in any significant amount.
A minion wave that catches up with its preceding wave starts pushing the lane towards enemy turret.
Big waves of minions can overwhelm a turret.
When a player interrupts an enemy minion wave by ensuring their side is making more damage to the opponents minions than they are receiving, the lane starts to push.
In simplest way this is made by killing every minion without interference from your own minions thus moving the point where the minion waves clash.
On more sophisticated turning the player makes sure their side is making just slightly more damage thus allowing the wave to build up as the wave gets reinforcements before than the enemy wave.
Some game terms related to minions:
Farming: Last hitting minions to earn gold and experience.
Lane Momentum: The strength with which the minions in a lane advance without champion aid.
Pushing: Attacking enemy minions to keep allied minions alive and allow them to advance along their lane.
Freezing: Preventing enemy minions from pushing the lane without pushing them back.
Winions: A wave of minions so big or so strong that it can destroy turrets, nexuses, or champions without champion aid.
Free Farming: Farming without being confronted by an enemy champion.
Proxy Farming: Farming behind an enemy tower. It's easier than conventional farming because there is no interference from allied minions, but it's usually much more dangerous.
Split Pushing: Attacking several objectives at the same time when at least one of the objectives is a lane turret.
These are all the Minions used between Beta 1 and Beta 3
These are all the Minions used between Beta 3 and second Summoner's Rift map update
These are all the Minions used after second Summoner's Rift map update
If the champions do not take part in the battle, the minions in one of the teams will eventually win the game. The team that wins is random.
When minions scan for a target, it is possible for a champion to pick up aggro multiple times from a minion. Minions can constantly pick up aggro from you and can follow you through the jungle.
By default, each player sees their allied minions and structures in Summoner's Rift in blue and the enemy minions and structures in red. This is just a visual effect, it has no practical effects in the game.