Drowning someone underwater?

[Silva Stormrage]

Hello, brief situation is that one of my players is being grappled by an aboleth at low hp. The player is pinned by the aboleth and the aboleth wants to try and force the player to start drowning, are there any rules for this? He could attack with a natural attack but it doesn't seem to reduce how long the player can hold his breath. Will I need to houserule something for this? If so what do you think is reasonable? Dealing half damage on an attack for halving the rounds of breath the player has left?

Thanks for your help.

[Greenish]

Given that drowning means automatic death, I'm not sure you want to make it too easy to inflict.

[Silva Stormrage]

Fair point we house rule that you can stop drowning by taking them out of the water and a dc 10 heal check. Its not quite instantly lethal. But it does seem like a reasonable tactic for an aboleth to preform.

[Ashtagon]

Don't forget that being involved in a grapple counts as strenuous work, so you halve the normal length of time you can hold your breath.

Forcing someone to drown effectively becomes a game of maintaining the grapple for long enough.

As a houserule, you could say that forcing someone to release their breath can be done by a pinning attacker. In such cases, I'd rule that the damage is halved (round down) and counted as lost rounds of holding-breath duration instead of hit point damage.