To start a grapple, you need to grab and hold your target. Starting a grapple requires a successful melee attack roll. If you get multiple attacks, you can attempt to start a grapple multiple times (at successively lower base attack bonuses).

Step 1: Attack of Opportunity. You provoke an attack of opportunity from the target you are trying to grapple. If the attack of opportunity deals damage, the grapple attempt fails. (Certain monsters do not provoke attacks of opportunity when they attempt to grapple, nor do characters with the Improved Grapple feat.) If the attack of opportunity misses or fails to deal damage, proceed to Step 2.

Step 2: Grab. You make a melee touch attack to grab the target. If you fail to hit the target, the grapple attempt fails. If you succeed, proceed to Step 3.

Step 3: Hold. Make an opposed grapple check as a free action.

If you succeed, you and your target are now grappling, and you deal damage to the target as if with an unarmed strike.

If you lose, you fail to start the grapple. You automatically lose an attempt to hold if the target is two or more size categories larger than you are.

In case of a tie, the combatant with the higher grapple check modifier wins. If this is a tie, roll again to break the tie.

Step 4: Maintain Grapple. To maintain the grapple for later rounds, you must move into the target’s space. (This movement is free and doesn’t count as part of your movement in the round.)

Moving, as normal, provokes attacks of opportunity from threatening opponents, but not from your target.

If you can’t move into your target’s space, you can’t maintain the grapple and must immediately let go of the target. To grapple again, you must begin at Step 1.