All of the close combat attacks, except Hammer of Wrath Attacks of a model with this special rule are resolved at AP2 (unless it's attacking with an AP1 weapon).
Isn't that great? All Riptide close combat attacks are resolved at AP2! This is definitely worth remembering, but the most interesting things about Smash is the next bit of the rule:
Additionally, when it makes its close combat attacks, it can choose to instead make a Smash Attack. If it does so, roll To Hit as normal, but halve its Attacks characteristic. A Smash Attack also doubles the model's Strength (to a maximum of l0) for the purposes of that Attack. Furthermore, a model making a Smash Attack can re-roll its armour penetration rolls, but must abide by the second result.
The great part of this rule is the definition of how many attacks it gets. Because when we halve a characteristic we round up, the Riptide gets two Smash attacks (3 attacks divided by 2 rounds up to 2).
But what if the Riptide charges into combat? This is where stuff gets interesting! We determine the bonus attacks from a Charge using the rules on p24 of the Basic Rule Book:
Each engaged model makes a number of Attacks (A) as indicated on its characteristics profile, plus the following bonus Attacks:
- + 1 Charge Bonus: Engaged models that charged this turn get + 1 Attack this turn.
So if a Riptide charges and chooses to Smash, does it get 2 Smash attacks (3 Attacks + 1 Attack, divided by 2 equals 4) or does it get 3 Smash attacks (3 attacks divided by 2 rounds up to 2, +1 additional Attack for the charge)?
Enter the FAQ to the rescue (p6 in the September 2013 Edition):
Q: The rulebook says that you halve your Attacks characteristic if you perform a Smash attack. However, if a Monstrous Creature has an uneven number of Attacks, (3 for example), but has charged that turn, does it receive the bonus Attack for charging before or after halving its Attacks? (p42)
A: You halve the model’s Attacks characteristic first, then apply any additional modifiers. In the example above, the model would halve its Attacks first (rounding up to 2), then receive a bonus Attack for charging.
Games Workshop actually produced a useful piece of information in a FAQ! And what's more, it benefits the Riptide immensely, especially if it charges something that it can actually hit! Tanks are my favorite target here as they are usually WS0 or WS1. Charging a Walker (like a Dreadnought) is possible too, but fraught with statistical danger if the Walker in question has a WS higher than 3!
So there you have it.... Enjoy Hulking up and Smashing your opponent with your Riptide.