Quick answer

Before a fight, identify who starts it, who deals sustained damage and who protects that damage dealer. You don't need to reach the enemy carry at any cost: a marksman who stays alive and hits the nearest safe target can contribute more than one who walks into danger.

Before a fight, identify who starts it, who deals sustained damage and who protects that damage dealer. You don't need to reach the enemy carry at any cost: a marksman who stays alive and hits the nearest safe target can contribute more than one who walks into danger.

A simple example

Imagine your team has a tank, a marksman, a mage, a support and a flanking fighter. The enemy has an assassin looking for your marksman. Before engaging, the tank checks that teammates can follow; the support stays near the marksman and keeps a defensive ability ready. The marksman attacks from behind the frontline, the mage uses spells from a safe angle, and the fighter looks for a flank without leaving the team in a 4v5.

Your job During the fight Common mistake
Frontline Take space and use control when your team is in range to follow. Charging alone beyond your team's reach.
Damage dealer Attack a reachable target while keeping an escape route. Crossing the enemy frontline just to hit a preferred target.
Protector Watch for the threat approaching your carry; save a suitable shield, heal or control ability. Using every defensive tool before the threat arrives.
Flanker Look for a safe route and communicate timing. Entering before teammates can act, or arriving after they have lost the fight.

Three checks before committing

  1. People: Are your allies close enough, alive and ready? If not, back away instead of forcing a fight.
  2. Position: Can you see the approach and leave if it goes badly? Don't walk alone into an unlit area to find out.
  3. Abilities: Which enemy engage or assassin can reach your carry? Keep an answer available when your role requires it.

After a fight, review one decision: did you enter alone, stand too close, or spend protection too early? Adjust that before the next objective. Champion kits and compositions differ, so treat these as examples rather than rigid assignments.

Sources: Riot: How to Play · Riot champion role example: Nautilus · League Wiki champion classes.

Sources