What reasons could a sword-fighter have to occasionally mix in a punch or kick?
EDIT: How did a whole class get into this post when I wasn't looking?
An unarmed strike is a light melee weapon that deals 1d3 points of nonlethal bludgeoning damage. Unarmed strikes are considered simple weapons for the purposes of proficiency, and you gain a +2 bonus on attack rolls made with them. In addition, you may apply the better of your Str or Dex modifiers to attack rolls. However, using an unarmed strike against an armed opponent provokes an attack of opportunity unless you have the Improved Unarmed Strike feat (creatures with primary natural attacks count as armed).
You may attack with an unarmed strike as if it were a manufactured or natural weapon, whichever is more convenient. This allows you to make iterative attacks with an unarmed strike if your BAB is high enough, and/or make an additional attack with an unarmed strike at a -5 penalty as part of a full attack in addition to your normal attacks.
Attempting a trip, bull rush, or grapple
does not provoke an attack of opportunity. However, when performing one of these attacks you may choose to deliver it via an unarmed strike, in which case you are treated as one size category larger than normal for opposed rolls made as part of that attack. Likewise, an unarmed strike is considered a two-handed weapon when making disarm attempts, or in any other case where the size of your weapon would give you an advantage.
Improved Unarmed Strike [General, Fighter]Prerequisite: Proficiency with unarmed strikes
Benefit: You may treat your unarmed strike as a natural or manufactured weapon at any point, whichever is more convenient, allowing it to benefit from spells which enhance natural or manufactured weapons. You no longer provoke an attack of opportunity for making an unarmed strike, and you can make attacks of opportunity against opponents who attack you with unarmed strikes as if you were armed. In addition, your unarmed strikes can deal lethal or nonlethal damage, at your option.
Special: This feat counts as Weapon Focus (unarmed strike) for the purposes of prerequisites.
Superior Unarmed Strike [General, Fighter]
Prerequisite: Improved Unarmed Strike
Benefit: You may treat your unarmed strike as a double weapon whenever convenient, allowing you to dual-wield two strikes or wield one with both hands. If you have applied enchantments to your unarmed strike by some means, they apply to both ends.
Special: This feat counts as Weapon Specialisation (unarmed strike) for the purposes of prerequisites. A monk may select this feat as one of his monk bonus feats.Decisive Strike [General, Fighter]Prerequisite: Power Attack
Benefit: When attacking with your unarmed strike as a manufactured weapon, you may treat it as a one-handed weapon, and may wield it in two hands if you wish (gaining 1.5x your Str bonus to damage). When attacking with your unarmed strike as a natural attack, it always deals damage as a primary natural attack (adding 1x your Str bonus to damage).
Normal: Attacks made with natural weapons after your normal attacks are secondary, adding 0.5x your Str bonus to damage.
Special: A monk may select this feat as one of his monk bonus feats.
Flurry of Blows [General, Fighter]Prerequisite: Two-Weapon Fighting or Multiattack
Benefit: When attacking with your unarmed strike as a manufactured weapon, you may treat it as a pair of light weapons. In addition, you gain a second unarmed strike which can only be used as a secondary natural attack (i.e. you cannot attack with it as a manufactured weapon). If you have applied enchantments to your unarmed strike by some means, they apply to both instances of your unarmed strike.
Special: A monk may select this feat as one of his monk bonus feats.
Semi-related random monkness
[spoiler]
Monk1 Improved Unarmed Strike, Ki strike, AC bonus, Fast movement
2 Evasion, Multiattack
3 Dancing strike, Still mind
4 Unarmed counter
5 Unarmed versatility
6 Improved Multiattack
7 Flight
8 Mountain strike
9 Improved unarmed counter
10 Flyby Attack
11 Rapidstrike
12 Improved evasion
13 Empty body (incorporeal)
14 Greater unarmed counter
15 Quivering palm
16 Improved Rapidstrike
17 Improved dancing strike
18 Empty body (ethereal)
19 Supreme unarmed counter
20 Perfect selfBonus feats: Monks receive Improved Unarmed Strike as a bonus feat at 1st level. They receive Multiattack at 2nd level, Improved Multiattack at 6th level, Rapidstrike at 11th level and Improved Rapidstrike at 16th level.
Ki Pool: A monk has a pool of ki equal to half his monk level + his Wis modifier. This stacks with any ki pool he may receive from other classes (such as ninja).
AC Bonus: As long as he does not wear armour or carry a shield, a monk gains a bonus to AC equal to the maximum size of his ki pool.
Ki Strike: A monk deals additional damage with natural weapons equal to the maximum size of his ki pool. As long as he has at least 1 point of ki remaining his attacks are treated as magic and
ghost touch weapons.
Fast Movement (Ex): A monk's land speed increases by +5ft per class level as long as he does not wear armour or carry a shield.
Dancing Strike (Ex): At 3rd level, whenever a monk makes one or more attacks he may make additional attacks with his unarmed strike, as with a full attack. For instance, as a standard action the monk could attack with a quarterstaff then make an additional attack with an unarmed strike at a -2 penalty. At 17th level a monk may make a full attack whenever he could make one or more attacks.
Unarmed Counter (Ex): At 4th level, a monk is treated as one size category larger than normal when defending against special attacks for which unarmed strikes grant a bonus. At every 5th level thereafter the monk is treated as another size category larger when making such special attacks or defending against them.
Unarmed Versatility (Ex): At 5th level, a monk gains Superior Unarmed Strike as a bonus feat. If he already possesses that feat he may select another feat from the list available to fighters, as long as he meets the prerequisites. In addition, on each unarmed strike he may choose to deal slashing, bludgeoning or piercing damage.
Flight (Su): At 7th level a monk can fly at a speed equal to his land speed with perfect maneuverability.
Mountain Strike (Ex): At 8th level a monk's attacks ignore damage reduction and hardness.
Empty Body (Su): As an immediate action, a monk of 13th level or higher can expend 1 point of ki to phase out of reality for 1 round; during this time he may choose to be treated as corporeal or incorporeal, whichever is more convenient at any given moment. Unlike most incorporeal creatures, he adds his Wis modifier as a deflection bonus to AC rather than his Cha modifier. At 18th level the monk may also choose to treat himself as ethereal during this time, and resolves all his attacks as touch attacks.
Quivering Palm (Ex): At 15th level, any creature struck by one or more of a monk's attacks must make a Fort save at the end of the round. Failure indicates that the creature is permanently paralysed or dies instantly, at the monk's choice.
Perfect Self: At 20th level a monk may treat himself as an Outsider instead of his normal type whenever it is more convenient. In addition he gains DR/epic equal to the maximum size of his ki pool.[/spoiler]