Monsters in Naval Combat (OSS)

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In many cases, a sea creature will menace a ship and its crew. The Detailed Naval Combat system can resolve these conflicts.
==Creature Movement==
Creatures use their swimming movement rates in naval combat. Their pursuit ratings are 1d6 plus one third of their swimming movement rates. Swimming creatures can tire, but not as readily as rowers do. Their maneuverability dice depend on creature size, modified by movement rate. Table 34 summarizes creature movement:
 Table 34: Creature Maneuverability and Pursuit
Creature Size	Many.	Pursuit
Tiny 	1d6+9	0
Small 	1d6+8	0
Man 	1d6+7	1
Large 	1d6+6	2
Huge 	1d6+5	3
Gargantuan 	1d6+6	4
: Creature Size: Refers to the creature's size class as noted in the MONSTROUS MANUAL™ Tome.
: Manv: Maneuverability dice. These work just like ship's maneuverability dice (see the Maneuvering Phase section). In addition, creatures receive a +1 bonus to maneuverability if their swimming movement rates are 12 or higher.
: Pursuit: As noted earlier, swimming creatures can tire as rowers do (see page 38). The number listed here is the number of checks the creature passes automatically during an encounter.
==Creatures and Missile Fire==
Archers (but not artillerists) aboard ships can fire at swimming creatures using their normal THAC0S and the target creature's Armor Class. Use Table 15 to determine how many archers hit. Each hit inflicts normal damage on the creature.
Completely submerged creatures become immune to missile fire. Partially submerged creatures gain a +8 Armor Class bonus.
==Creatures and Artillery Fire==
Artillery can fire at Huge and Gargantuan creatures just as it does at ships-smaller creatures and fully submerged creatures of any size are immune to artillery fire.
Refer to Table 35 if an artillery hit strikes a creature. Do not roll on Table 22.
 Table 35: Artillery vs. Creatures
Weapon 	Damage
Ballista, light 	3d6
Ballista, medium 	3d8
Ballista, heavy 	3d12
Catapult, light 	2d10
Catapult, medium 	3d10
Catapult, heavy 	3d10
Greek Fire Projector	3d10*
Trebuchet 	4d10
: * A successful saving throw vs. breath weapon reduces damage by half. Regardless of the success or failure of the saving throw, the victim suffers 1d10 points of damage each round for the next two rounds.
==Creatures and Ramming==
It is possible for some creatures to make ramming attempts or to be rammed. Crippling rams have no effect on creatures. If a vessel rams a creature, do not roll on Table 24. Otherwise, a creature's effectiveness in ramming combat depends on its size and armor class as noted below:
 Table 36: Creatures and Ramming
Creature Size	Rams AsVessel Size	DamageSuffered**
Tiny 	— 	—
Small 	— 	—
Man 	— 	—
Large 	Small 	2d8
Huge 	3d10 	
Gargantuan 	Large 	4d10
: ** A successful saving throw vs. breath weapon reduces damage by half. Crippling rams have no effect on creatures. A vessel's ramming factor applies as a penalty to the saving throw.
Creatures roll on Table 24 when ramming vessels; adjust the roll according to the relative size of the creature and its target (see page 46) and for the creature's armor class, as noted below:
 Table 37: Creature Ramming Effects
Armor Class 	Adjustment*
8 or less 	-1
7-5 	0
4-2 	+1
1 to -1 	+2
-3 to -4 	+3
-5 or better	+4
: * Bonus or penalty to rolls on Table 24: Ramming Action Results.
If the roll on Table 24 indicates damage to the ramming vessel, the creature suffers the listed damage, but no other special effects. If the creature makes a Deadly Strike, it has the standard chance to get stuck; however, it can free itself with a successful Dexterity check. Assume a creature has a Dexterity score equal to one half its fastest movement rate.
==Creatures and Boarding==
Sea creatures can clamber aboard target vessels using the normal boarding procedures. Gargantuan creatures can simply reach onto a ship deck, so they need not attempt boarding rolls. If the attacking creatures can climb the defending vessel's sides, they ignore grappled or partially grappled effects and simply storm aboard (see Table 27). If the boarding combat roll gives one of these results, one quarter of the boarders get aboard instead.
Ships boarded by swimming creatures generally remain free to maneuver unless the some of the attackers stay behind in the sea and attempt to keep the ship from moving. Two Man-sized creatures can immobilize a Small vessel this way. Larger vessels require 15 creatures, plus another 15 for each size class of the target vessel above medium.
For example, it takes 45 man-sized creatures to immobilize a Very Large vessel. For this purpose, four Tiny or two Small creatures equal one Man-sized one. A Large creature counts as two man-sized creatures, and Huge creatures count as four. A Gargantuan creature can hold any vessel immobile so long as it is not more than twice as long as itself.
Boarding melees with sea creatures are conducted according to the normal procedures (see page 50). If groups of marines attack a single creature, use Table 15 to determine how many marines hit. Each hit inflicts normal damage on the creature. Likewise, if only a few creatures board a ship, divide the defending marines into groups and use Table 15 to resolve the resulting battles.