Attacker Stage 1: STR+Brawl - DEF is rolled to clinch/tackle/grab an opponent (nWoD, p157)

Attacker Stage 2: STR+Brawl - STR is rolled to overpower an opponent after stage 1 (nWoD, p157)

Victim Stage 1: STR+Brawl - STR is rolled to break out of the hold (nWoD, p157)

Victim Stage 1: STR+Brawl - STR is rolled to overpower and perform a grapple himself on his assailant (nWoD, p157)

Victim Stage 2: STR+Brawl - STR vs Assailant's Stage 2 successes to break out of the grapple (nWoD, p158)

If a character is actively grappled, they lose their defense bonus against attacks external to the grapple (house)

If a character is actively grappling, they still get their defense bonus against attacks external to the grapple (house)

A grappled or grappling character can be targeted for non-ranged attacks by characters not involved in the grapple without penalties (other than defense for the grappling character). (house)

A grappling character loses his ability to dodge

Automatic weapon: Roll ranged attack against all characters involved in a grapple (nWoD p160)

Single shot: -2 for each character you try to avoid shooting involved the grapple (nWoD p162)